Exhibit 4.1


 





SUPPLEMENTAL INDENTURE



dated as of June 9, 2016



among



AETNA INC.,





and



U.S. BANK NATIONAL ASSOCIATION,

as Trustee






 


 



 


Floating Rate Senior Notes due December
8, 2017


 


1.700% Senior Notes due June 7, 2018


 


1.900% Senior Notes due June 7, 2019


 


2.400% Senior Notes due June 15, 2021


 


2.800% Senior Notes due June 15, 2023


 


3.200% Senior Notes due June 15, 2026


 


4.250% Senior Notes due June 15, 2036


 


4.375% Senior Notes due June 15, 2046


 




    	 



    	 



    

TABLE OF CONTENTS 


 



Page


 




	Article 1 
Definitions
	Section 1.01.  Definitions	2
	Section 1.02.  Section References	7
	Article 2 
The Notes
	Section 2.01.  Issue of Notes	7
	Section 2.02.  Stated Maturity	8
	Section 2.03.  Notes Issuable as Global Securities	8
	Section 2.04.  Interest and Payment	9
	Section 2.05.  Payment of Principal, Premium and Interest	13
	Section 2.06.  Optional Redemption	13
	Section 2.07.  Special Mandatory Redemption	17
	Section 2.08.  Change of Control Offer to Purchase	17
	Section 2.09.  Applicability of Certain Provisions of the Base Indenture in Respect of the Notes	19
	Section 2.10.  Registrar and Paying Agent; Calculation Agent	19
	Section 2.11.  No Sinking Fund	19
	Section 2.12.  Minimum Denominations	19
	Article 3 
Miscellaneous
	Section 3.01.  Relation to Indenture	20
	Section 3.02.  Continued Effect	20
	Section 3.03.  Provisions Binding on Company’s Successors	20
	Section 3.04.  Certain Trustee Matters	20
	Section 3.05.  Governing Law	20
	Section 3.06.  Counterparts	20
	 	 




	Exhibit A  Form of Floating Rate Senior Note due 2017	A-1
	Exhibit B  Form of 1.700% Senior Note due 2018	B-1
	Exhibit C  Form of 1.900% Senior Note due 2019	C-1
	Exhibit D  Form of 2.400% Senior Note due 2021	D-1
	Exhibit E  Form of 2.800% Senior Note due 2023	E-1
	Exhibit F  Form of 3.200% Senior Note due 2026	F-1
	Exhibit G  Form of 4.250% Senior Note due 2036	G-1
	Exhibit H  Form of 4.375% Senior Note due 2046	H-1




    	i 



    	 



    

SUPPLEMENTAL INDENTURE (this “Supplemental
Indenture”), dated as of June 9, 2016, between AETNA INC., a corporation duly organized and validly existing under the
laws of the Commonwealth of Pennsylvania (the “Company”), having its principal office at 151 Farmington Avenue,
Hartford, Connecticut 06156 and U.S. BANK NATIONAL ASSOCIATION, as successor-in-interest to State Street Bank and Trust Company,
as trustee (the “Trustee”).


 


RECITALS


 


WHEREAS, the Company and the Trustee entered
into a Senior Indenture dated as of March 2, 2001 (the “Base Indenture”, and as supplemented by this
Supplemental Indenture, the “Indenture”) providing for the issuance from time to time of the Company’s
debentures, notes or other evidences of indebtedness (the “Securities”), to be issued in one or more series
as in the Base Indenture provided;


 


WHEREAS, Sections 201 and 301 of the Base
Indenture provide that the Company and the Trustee may establish the terms of a new series of Securities in an indenture supplemental
to the Base Indenture;


 


WHEREAS, Section 901 of the Base Indenture
provides that the Company and the Trustee may enter into an indenture supplemental to the Base Indenture, without the consent of
any Holders, to eliminate any of the provisions of the Base Indenture in respect of a new series of Securities so established pursuant
to Section 301 of the Base Indenture;


 


WHEREAS, pursuant to resolutions adopted
by the Board of Directors of the Company on July 2, 2015 and the Delegation of Authority of Mark T. Bertolini, Chairman and Chief
Executive Officer of the Company, dated May 27, 2016 (collectively, the “Company Resolutions”), the Company
has approved to be established eight new series of Securities, designated as its Floating Rate Senior Notes due December 8, 2017
(the “Floating Rate Notes”), its 1.700% Senior Notes due June 7, 2018 (the “2018 Notes”),
its 1.900% Senior Notes due June 7, 2019 (the “2019 Notes”), its 2.400% Senior Notes due June 15, 2021 (the
“2021 Notes”), its 2.800% Senior Notes due June 15, 2023 (the “2023 Notes”), its 3.200% Senior
Notes due June 15, 2026 (the “2026 Notes”), its 4.250% Senior Notes due June 15, 2036 (the “2036 Notes”)
and its 4.375% Senior Notes due June 15, 2046 (the “2046 Notes” and together with the 2018 Notes, the 2019 Notes,
the 2021 Notes, the 2023 Notes, the 2026 Notes and the 2036 Notes, the “Fixed Rate Notes” and, the Fixed Rate
Notes together with the Floating Rate Notes, the “Notes”) as in this Supplemental Indenture provided; and


 


WHEREAS, all requirements necessary to make
this Supplemental Indenture a valid, binding and enforceable instrument in accordance with its terms and to make the Notes, when
executed, authenticated and delivered by the Company, the valid, binding and enforceable obligations of the Company have been done
and performed.


 




    1


     


    

NOW, THEREFORE, in consideration of the
premises and mutual covenants herein contained and intending to be legally bound, the parties to this Supplemental Indenture hereby
agree as follows:


 


Article
1

Definitions


 


Section 1.01.            Definitions.


 


(a)            Capitalized terms used herein and
not otherwise defined herein have the respective meanings assigned to them in the Base Indenture.


 


(b)            The following terms shall have the
meanings assigned to them in this ‎‎Section 1.01(b):


 


“2018 Notes” has the
meaning stated in the fourth recital of this Supplemental Indenture.


 


“2019 Notes” has the
meaning stated in the fourth recital of this Supplemental Indenture.


 


“2021 Notes” has the
meaning stated in the fourth recital of this Supplemental Indenture.


 


“2023 Notes” has the
meaning stated in the fourth recital of this Supplemental Indenture.


 


“2026 Notes” has the
meaning stated in the fourth recital of this Supplemental Indenture.


 


“2036 Notes” has the
meaning stated in the fourth recital of this Supplemental Indenture.


 


“2046 Notes” has the
meaning stated in the fourth recital of this Supplemental Indenture.


 


“Base Indenture” has
the meaning stated in the first recital of this Supplemental Indenture.


 


“Below Investment Grade Rating
Event” means the Notes of a series are rated below an Investment Grade Rating by each of the Rating Agencies on any date
from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention to effect
a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a Change of
Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however, that if
(i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Notes of such series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement


 




    2


     


    

would
result in a Below Investment Grade Rating Event for such series of Notes, then such 60-day period shall be extended for such time
as the rating of the Notes of such series by any such Rating Agency remains under publicly announced consideration for possible
downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment Grade
Rating could cause a Below Investment Grade Rating Event for such series of Notes. Notwithstanding the foregoing, a rating event
otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of a particular
Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for any series of Notes for purposes of the
definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to which this definition
would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s or the Trustee’s
request that the reduction was the result, in whole or in part, of any event or circumstance comprised of or arising as a result
of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control has occurred at the time
of the rating event).


 


“Business Day”, when
used with respect to any Place of Payment, means each Monday, Tuesday, Wednesday, Thursday and Friday which is not a day on which
banking institutions in that Place of Payment are authorized or obligated by law or executive order to close.


 


“Calculation Agent” means
U.S. Bank National Association, or its successor appointed as such by the Company.


 


“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than
by way of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or
assets of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3)
of the Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including,
without limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in
Section 13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly
or indirectly, of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however,
that a transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a
holding company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 




    3


     


    

“Change of Control Offer”
has the meaning stated in ‎‎Section 2.08(a) of this Supplemental
Indenture.


 


“Change of Control Payment”
has the meaning stated in ‎‎Section 2.08(a) of this Supplemental
Indenture.


 


“Change of Control Payment Date”
has the meaning stated in ‎‎Section 2.08(a) of this Supplemental
Indenture.


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Company” means the Person
named as the “Company” in the first paragraph of this Supplemental Indenture until a successor Person shall have become
such pursuant to the applicable provisions of the Indenture, and thereafter “Company” shall mean such successor Person.


 


“Company Resolutions”
has the meaning stated in the fourth recital of this Supplemental Indenture.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Fixed Rate Notes to be redeemed, calculated as if the Stated Maturity of the principal
of the Fixed Rate Notes were June 7, 2018 (in the case of the 2018 Notes), June 7, 2019 (in the case of the 2019 Notes), May 15,
2021 (in the case of the 2021 Notes), April 15, 2023 (in the case of the 2023 Notes), March 15, 2026 (in the case of the 2026 Notes),
December 15, 2035 (in the case of the 2036 Notes) or December 15, 2045 (in the case of the 2046 Notes) (in each case, the “Remaining
Life” of the Fixed Rate Notes of such series) that would be utilized, at the time of selection and in accordance with
customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the Remaining Life of
the Fixed Rate Notes of such series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Fixed Rate Notes of a series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“DTC” means The Depository
Trust Company.


 


“End Date” has the meaning
ascribed to such term in the Merger Agreement.


 


“Exchange Act” means
the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Fixed Rate Notes” has
the meaning stated in the fourth recital of this Supplemental Indenture.


 




    4


     


    

“Floating Rate Interest Determination
Date” has the meaning stated in ‎Section 2.04(a)(ii)
of this Supplemental Indenture.


 


“Floating Rate Interest Payment
Date” has the meaning stated in ‎Section 2.04(a)(i)
of this Supplemental Indenture.


 


“Floating Rate Interest Period”
has the meaning stated in ‎Section 2.04(a)(i) of this
Supplemental Indenture.


 


“Floating Rate Notes”
has the meaning stated in the fourth recital of this Supplemental Indenture.


 


“Floating Rate Regular Record Date”
has the meaning stated in ‎Section 2.04(a)(i) of this Supplemental
Indenture.


 


“Humana” means Humana
Inc., a Delaware corporation.


 


“Indenture” has the meaning
stated in the first recital of this Supplemental Indenture.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under the circumstances permitting
the Company to select a replacement agency and in the manner for selecting a replacement agency, in each case as set forth in the
definition of “Rating Agencies.”


 


“London Business Day”
shall mean any calendar day on which commercial banks are open for dealings in deposits in U.S. dollars in the London interbank
market.


 


“Merger” means the acquisition
of Humana by the Company on the terms and subject to the conditions set forth in the Merger Agreement.


 


“Merger Agreement” means
the Agreement and Plan of Merger, dated as of July 2, 2015, among the Company, Echo Merger Sub, Inc., Echo Merger Sub, LLC and
Humana, as amended from time to time.


 


“Moody’s” means
Moody’s Investors Service, Inc.


 


“Notes” has the meaning
stated in the fourth recital of this Supplemental Indenture.


 




    5


     


    

“Primary Treasury Dealer”
has the meaning stated in the definition of “Reference Treasury Dealer” in this ‎‎Section
1.01(b).


 


“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Notes of a series
or fails to make a rating of the Notes of such series publicly available for reasons outside of the Company’s control, a
“nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange Act
that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may be,
with respect to such series of Notes.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 


“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


“Remaining Life” has
the meaning stated in the definition of “Comparable Treasury Issue” in this ‎Section
1.01(b).


 


“Securities” has the
meaning stated in the first recital of this Supplemental Indenture and more particularly means any Securities authenticated and
delivered under the Indenture, including, without limitation, the Notes.


 


“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


“Special Mandatory Redemption Date”
means the 30th day (or if such day is not a Business Day, the first Business Day thereafter) following the transmission of a notice
of special mandatory redemption.


 


“Special Mandatory Redemption Notes”
means the 2019 Notes, the 2021 Notes, the 2026 Notes, the 2036 Notes and the 2046 Notes.


 


“Supplemental Indenture”
has the meaning stated in the first paragraph of this instrument.


 


“Three-Month LIBOR” has
the meaning stated in ‎Section 2.04(a)(iv) of this Supplemental
Indenture.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Fixed Rate Notes of a series,


 




    6


     


    

		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before or after the Remaining Life for the Fixed Rate Notes of
such series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined
and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding to the nearest
month), or



 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Trustee” means the Person
named as the “Trustee” in respect of the Notes in the first paragraph of this Supplemental Indenture until a successor
Trustee in respect of the Notes shall have become such pursuant to the applicable provisions of the Indenture, and thereafter “Trustee”
shall mean or include such Person who is then a Trustee in respect of the Notes.


 


Section 1.02.            Section References.
Each reference to a particular section set forth in this Supplemental Indenture shall, unless the context otherwise requires,
refer to this Supplemental Indenture. Each reference to a particular section of the Base Indenture shall refer to that particular
section of the Base Indenture.


 


Article
2

The Notes


 


Section 2.01.            Issue of Notes. The
Notes shall be issued as eight series of Securities under the Base Indenture as supplemented by this Supplemental Indenture, which
such series shall be known and designated as the “Floating Rate Notes due December 8, 2017”, the “1.700% Senior
Notes due June 7, 2018”, the “1.900% Senior Notes due June 7, 2019”, the “2.400% Senior Notes due June
15, 2021”, the “2.800% Senior Notes due June 15, 2023”, the “3.200% Senior Notes due June 15, 2026”,
the “4.250% Senior Notes due June 15, 2036” and the “4.375% Senior Notes due June 15, 2046” of the Company.
Each series of Notes shall constitute a separate series of


 




    7


     


    

Securities
for all purposes under the Indenture. The Notes shall be unsecured. The Notes shall be executed, authenticated and delivered in
accordance with the provisions of the Indenture. The aggregate principal amount of the Floating Rate Notes which may be authenticated
and delivered under the Indenture is initially limited to $500,000,000, the aggregate principal amount of the 2018 Notes which
may be authenticated and delivered under the Indenture is initially limited to $1,000,000,000, the aggregate principal amount
of the 2019 Notes which may be authenticated and delivered under the Indenture is initially limited to $1,650,000,000, the aggregate
principal amount of the 2021 Notes which may be authenticated and delivered under the Indenture is initially limited to $1,850,000,000,
the aggregate principal amount of the 2023 Notes which may be authenticated and delivered under the Indenture is initially limited
to $1,300,000,000, the aggregate principal amount of the 2026 Notes which may be authenticated and delivered under the Indenture
is initially limited to $2,800,000,000, the aggregate principal amount of the 2036 Notes which may be authenticated and delivered
under the Indenture is initially limited to $1,500,000,000 and the aggregate principal amount of the 2046 Notes which may be authenticated
and delivered under the Indenture is initially limited to $2,400,000,000 (except, in each case, for such Notes authenticated and
delivered upon registration of transfer of, or in exchange for, or in lieu of, other Notes of the same series pursuant to Sections
304, 305, 306, 906 or 1107 of the Base Indenture and except for any Notes which, pursuant to Section 303 of the Base Indenture,
are deemed never to have been authenticated and delivered thereunder). Additional Notes of a series may be authenticated and delivered
from time to time as contemplated in Section 301 of the Base Indenture; provided that if the additional Notes of a series
are not fungible with the Notes of such series for United States Federal income tax purposes, the additional Notes of the series
will have a separate CUSIP number. The entire amount of Notes of each series may immediately be executed by the Company and delivered
to the Trustee and shall be authenticated by the Trustee and delivered to or upon the order of the Company pursuant to Section
303 of the Base Indenture.


 


Section 2.02.            Stated Maturity. The
Stated Maturity of the principal of the Floating Rate Notes shall be December 8, 2017, the Stated Maturity of the principal of
the 2018 Notes shall be June 7, 2018, the Stated Maturity of the principal of the 2019 Notes shall be June 7, 2019, the Stated
Maturity of the principal of the 2021 Notes shall be June 15, 2021, the Stated Maturity of the principal of the 2023 Notes shall
be June 15, 2023, the Stated Maturity of the principal of the 2026 Notes shall be June 15, 2026, the Stated Maturity of the principal
of the 2036 Notes shall be June 15, 2036, and the Stated Maturity of the principal of the 2046 Notes shall be June 15, 2046.


 


Section 2.03.            Notes Issuable as Global
Securities.


 


(a)            The Notes shall be issued in the
form of one or more Global Securities registered in the name of DTC or its nominee, to be deposited with, or on behalf of, DTC,
New York, New York.


 


(b)            The Notes shall be in such form
or forms as may be approved by the officers of the Company as provided in the Company Resolutions, such approval to be evidenced
by any such officer’s manual or facsimile signature on the Notes, provided that


 




    8


     


    

such
forms of the Notes are not inconsistent with the requirements of the Indenture or the Company Resolutions and are substantially
in the applicable form or forms attached hereto as Exhibits A through H.


 


Section 2.04.            Interest and Payment.


 


(a)            This ‎Section
2.04(a) shall only apply to the Floating Rate Notes.


 


(i)            The Floating Rate Notes
shall bear interest from June 9, 2016, or from the most recent Floating Rate Interest Payment Date to which interest has been paid
or duly provided for, as the case may be (each of these periods, a “Floating Rate Interest Period”), at a rate
per annum equal to the Three-Month LIBOR as determined on the applicable Floating Rate Interest Determination Date plus 0.650%,
payable on each Floating Rate Interest Payment Date, beginning September 8, 2016, to the Person in whose name such Floating Rate
Notes (or one or more predecessor Floating Rate Notes) are registered at the close of business on the Regular Record Date next
preceding the applicable Floating Rate Interest Payment Date. Each March 8, June 8, September 8 and December 8 shall be a “Floating
Rate Interest Payment Date” for the Floating Rate Notes, and the February 21, May 24, August 24 or November 23 (whether
or not a Business Day), as the case may be, next preceding a Floating Rate Interest Payment Date shall be the “Floating
Rate Regular Record Date” for the interest payable on such Floating Rate Interest Payment Date.


 


(ii)            The Floating Rate Notes
shall bear interest at a rate for each applicable Floating Rate Interest Period that is determined by the Calculation Agent on
the second London Business Day immediately preceding the first day of such Floating Rate Interest Period (each a “Floating
Rate Interest Determination Date”), and computed on the basis of a 360-day year and the actual number of days that have
elapsed in the applicable Floating Rate Interest Period. The Calculation Agent has set the initial interest rate on the Floating
Rate Notes at 1.3066% per annum and will reset such interest rate for each Floating Rate Interest Period on the Floating Rate Interest
Payment Date for the preceding Floating Rate Interest Period. Promptly after a Floating Rate Interest Determination Date, the Calculation
Agent will inform the Company of the interest rate for the next Floating Rate Interest Period. Upon written request from any registered
Holder of Floating Rate Notes, the Calculation Agent will provide the interest rate in effect on the Floating Rate Notes for the
current Floating Rate Interest Period and, if such written request is made after the applicable Floating Rate Interest Determination
Date, the interest rate to be in effect for the next applicable Floating Rate Interest Period.


 


(iii)            In any case where any
Floating Rate Interest Payment Date, other than the date of Stated Maturity, falls on a day that is not a Business Day, then such
Floating Rate Interest Payment Date shall be postponed to the next day that is a Business Day, except that, if such Business Day
falls in the next succeeding calendar month, then, unless it relates to interest payable at the date of Stated


 




    9


     


    

Maturity, such Floating Rate
Interest Payment Date shall be the immediately preceding Business Day. If the date of Stated Maturity of the Floating Rate Notes
falls on a day that is not a Business Day, then the related payment of principal and interest will be made on the next day that
is a Business Day with the same effect as if as if made on the date that the payment was first due, and no interest will accrue
on the amount so payable for the period from the date of Stated Maturity.


 


(iv)            The “Three-Month
LIBOR” shall be equal to, as of any applicable Floating Rate Interest Determination Date:


 


(A)            The offered rate to leading
banks in the London interbank market for deposits in U.S. dollars having an index maturity of three months, as such rate appears:


 


(1)            on the Reuters Monitor
Money Rates Service (“Reuters”) page LIBOR 01 (or on such other page as may replace Reuters page LIBOR 01 on
that service); or


 


(2)            if on such Floating Rate
Interest Determination Date, three-month LIBOR does not appear or is not available on Reuters page LIBOR 01 (or such other page
as may replace Reuters page LIBOR 01 on that service), on such other comparable publicly available service for displaying offered
rates for deposits in U.S. dollars in the London interbank market as may be selected by the Company with the consent of the Calculation
Agent,


 


in each case as of approximately 11:00 a.m., London
time, on such Floating Rate Interest Determination Date.


 


(B)            If such rate does not
appear on either of the pages described in clauses (A)(1) or (2) above, the Three-Month LIBOR, in respect of such Floating Rate
Interest Determination Date, will be determined as follows:


 


(1)            the Calculation Agent will
request the principal London offices of each of four major reference banks in the London interbank market, as selected by the Calculation
Agent (after consultation with the Company), to provide the Calculation Agent with its offered quotation for deposits in U.S. dollars
for the period of three months beginning on the applicable Floating Rate Interest Determination Date, to prime banks in the London
interbank market at approximately 11:00 a.m., London time, on that Floating Rate Interest Determination Date and in a principal
amount of not less than $1,000,000 for a single transaction in U.S. dollars in such market at such time. If at least two quotations
are provided to the Calculation Agent, then the


 




    10


     


    

Three-Month LIBOR on such Floating
Rate Interest Determination Date will be the arithmetic mean of such quotations.


 


(2)            If fewer than two such
quotations are provided, then the Three-Month LIBOR on such Floating Rate Interest Determination Date will be the arithmetic mean
of the rates quoted at approximately 11:00 a.m., New York City time, on such Floating Rate Interest Determination Date by three
major reference banks in New York City selected by the Calculation Agent (after consultation with the Company) for loans in U.S.
dollars to leading European banks, having an index maturity of three months and in a principal amount of not less than $1,000,000
for a single transaction in U.S. dollars in such market at such time.


 


provided, however, that if the banks selected
by the Calculation Agent are not providing quotations in the manner described in clause (B)(2), the Three-Month LIBOR determined
as of such Floating Rate Interest Determination Date will be the Three-Month LIBOR in effect for the prior applicable Floating
Rate Interest Period


 


(v)            All percentages resulting
from any calculation of any interest rate for the Floating Rate Notes will be rounded, if necessary, to the nearest one hundred
thousandth of a percentage point, with five one-millionths of a percentage point rounded upward (e.g., 3.876545% (or .03876545)
would be rounded to 3.87655% (or .0387655)), and all U.S. dollar amounts will be rounded to the nearest cent, with one-half cent
being rounded upward. Each calculation of the interest rate on the Floating Rate Notes by the Calculation Agent will (in the absence
of manifest error) be final and binding on the holders of the Floating Rate Notes, the Trustee and the Company.


 


(vi)            The interest rate on
the Floating Rate Notes shall in no event be higher than the maximum rate permitted by New York law or other applicable state law
as such law may be modified by United States law of general application. Additionally, the interest rate on the Floating Rate Notes
shall in no event be lower than zero percent.


 


(b)            The 2018 Notes shall bear interest
at the rate of 1.700% per annum, which shall accrue from June 9, 2016, or from the most recent Interest Payment Date to which interest
has been paid or duly provided for, as the case may be, payable semi-annually on June 7 and December 7 in each year, beginning
December 7, 2016, to the Person in whose name such Notes (or one or more predecessor Notes) are registered at the close of business
on the Regular Record Date next preceding the Interest Payment Date. Each June 7 and December 7 shall be an “Interest Payment
Date” for the 2018 Notes, and the May 23 or November 22 (whether or not a Business Day), as the case may be, next


 




    11


     


    

preceding
an Interest Payment Date shall be the “Regular Record Date” for the interest payable on such Interest Payment Date
on the 2018 Notes.


 


(c)            The 2019 Notes shall bear interest
at the rate of 1.900% per annum, which shall accrue from June 9, 2016, or from the most recent Interest Payment Date to which interest
has been paid or duly provided for, as the case may be, payable semi-annually on June 7 and December 7 in each year, beginning
December 7, 2016, to the Person in whose name such Notes (or one or more predecessor Notes) are registered at the close of business
on the Regular Record Date next preceding the Interest Payment Date. Each June 7 and December 7 shall be an “Interest Payment
Date” for the 2019 Notes, and the May 23 or November 22 (whether or not a Business Day), as the case may be, next preceding
an Interest Payment Date shall be the “Regular Record Date” for the interest payable on such Interest Payment Date
on the 2019 Notes.


 


(d)            The 2021 Notes shall bear interest
at the rate of 2.400% per annum, which shall accrue from June 9, 2016, or from the most recent Interest Payment Date to which interest
has been paid or duly provided for, as the case may be, payable semi-annually on June 15 and December 15 in each year, beginning
December 15, 2016, to the Person in whose name such Notes (or one or more predecessor Notes) are registered at the close of business
on the Regular Record Date next preceding the Interest Payment Date. Each June 15 and December 15 shall be an “Interest Payment
Date” for the 2021 Notes, and the June 1 or December 1 (whether or not a Business Day), as the case may be, next preceding
an Interest Payment Date shall be the “Regular Record Date” for the interest payable on such Interest Payment Date
on the 2021 Notes.


 


(e)            The 2023 Notes shall bear interest
at the rate of 2.800% per annum, which shall accrue from June 9, 2016, or from the most recent Interest Payment Date to which interest
has been paid or duly provided for, as the case may be, payable semi-annually on June 15 and December 15 in each year, beginning
December 15, 2016, to the Person in whose name such Notes (or one or more predecessor Notes) are registered at the close of business
on the Regular Record Date next preceding the Interest Payment Date. Each June 15 and December 15 shall be an “Interest Payment
Date” for the 2023 Notes, and the June 1 or December 1 (whether or not a Business Day), as the case may be, next preceding
an Interest Payment Date shall be the “Regular Record Date” for the interest payable on such Interest Payment Date
on the 2023 Notes.


 


(f)            The 2026 Notes shall bear interest
at the rate of 3.200% per annum, which shall accrue from June 9, 2016, or from the most recent Interest Payment Date to which interest
has been paid or duly provided for, as the case may be, payable semi-annually on June 15 and December 15 in each year, beginning
December 15, 2016, to the Person in whose name such Notes (or one or more predecessor Notes) are registered at the close of business
on the Regular Record Date next preceding the Interest Payment Date. Each June 15 and December 15 shall be an “Interest Payment
Date” for the 2026 Notes, and the June 1 or December 1 (whether or not a Business Day), as the case may be, next preceding
an Interest Payment Date shall be the “Regular Record Date” for the interest payable on such Interest Payment Date
on the 2026 Notes.


 




    12


     


    

(g)            The 2036 Notes shall bear interest
at the rate of 4.250% per annum, which shall accrue from June 9, 2016, or from the most recent Interest Payment Date to which interest
has been paid or duly provided for, as the case may be, payable semi-annually on June 15 and December 15 in each year, beginning
December 15, 2016, to the Person in whose name such Notes (or one or more predecessor Notes) are registered at the close of business
on the Regular Record Date next preceding the Interest Payment Date. Each June 15 and December 15 shall be an “Interest Payment
Date” for the 2036 Notes, and the June 1 or December 1 (whether or not a Business Day), as the case may be, next preceding
an Interest Payment Date shall be the “Regular Record Date” for the interest payable on such Interest Payment Date
on the 2036 Notes.


 


(h)            The 2046 Notes shall bear interest
at the rate of 4.375% per annum, which shall accrue from June 9, 2016, or from the most recent Interest Payment Date to which interest
has been paid or duly provided for, as the case may be, payable semi-annually on June 15 and December 15 in each year, beginning
December 15, 2016, to the Person in whose name such Notes (or one or more predecessor Notes) are registered at the close of business
on the Regular Record Date next preceding the Interest Payment Date. Each June 15 and December 15 shall be an “Interest Payment
Date” for the 2046 Notes, and the June 1 or December 1 (whether or not a Business Day), as the case may be, next preceding
an Interest Payment Date shall be the “Regular Record Date” for the interest payable on such Interest Payment Date
on the 2046 Notes.


 


(i)            Interest on the Fixed Rate Notes
will be computed on the basis of a 360-day year comprised of twelve 30-day months. In any case where any Interest Payment Date
for any Fixed Rate Note is not a Business Day, then payment of interest may be made on the next succeeding Business Day without
any additional amount being payable in respect of any delay.


 


Section 2.05.            Payment of Principal,
Premium and Interest. Payment of the principal of and premium, if any, and interest on the Notes will be made at the office
or agency of the Company maintained for that purpose in the United States of America; provided, however, that at
any time that the Notes are not represented by Global Securities, at the option of the Company, payment of interest may be made
by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register.


 


Section 2.06.            Optional Redemption.


 


(a)            The Company does not have the right
to redeem the Floating Rate Notes before the Stated Maturity of the principal of the Floating Rate Notes.


 


(b)            At any time, the 2018 Notes will
be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice by mail, in whole or in part,
at the election of the Company, at a Redemption Price equal to the greater of:


 


(i)            100% of the principal
amount of the 2018 Notes being redeemed, or


 




    13


     


    

(ii)            the sum of the present
value of (x) 100% of the principal amount of the 2018 Notes being redeemed and (y) all required remaining scheduled interest payments
due on the 2018 Notes being redeemed, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day
year consisting of twelve 30-day months) at the Treasury Rate plus 15 basis points,


 


plus, in each case, any interest
accrued but not paid to, but excluding, the Redemption Date.


 


(c)            At any time, the 2019 Notes will
be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice by mail, in whole or in part,
at the election of the Company, at a Redemption Price equal to the greater of:


 


(i)            100% of the principal
amount of the 2019 Notes being redeemed, or


 


(ii)            the sum of the present
value of (x) 100% of the principal amount of the 2019 Notes being redeemed and (y) all required remaining scheduled interest payments
due on the 2019 Notes being redeemed, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day
year consisting of twelve 30-day months) at the Treasury Rate plus 15 basis points,


 


plus, in each case, any interest
accrued but not paid to, but excluding, the Redemption Date.


 


(d)            At any time prior to May 15, 2021,
the 2021 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice by mail,
in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


(i)            100% of the principal
amount of the 2021 Notes being redeemed, or


 


(ii)            the sum of the present
value of (x) 100% of the principal amount of the 2021 Notes being redeemed and (y) all required remaining scheduled interest payments
due on the 2021 Notes being redeemed, in each case calculated as if the Stated Maturity of the principal of the 2021 Notes were
May 15, 2021, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve
30-day months) at the Treasury Rate plus 20 basis points,


 


plus, in each case, any interest
accrued but not paid to, but excluding, the Redemption Date.


 


(e)            At any time on or after May 15,
2021, the 2021 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of


 




    14


     


    

the
principal amount of the 2021 Notes being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


(f)            At any time prior to April 15, 2023,
the 2023 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice by mail,
in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


(i)            100% of the principal
amount of the 2023 Notes being redeemed, or


 


(ii)            the sum of the present
value of (x) 100% of the principal amount of the 2023 Notes being redeemed and (y) all required remaining scheduled interest payments
due on the 2023 Notes being redeemed, in each case calculated as if the Stated Maturity of the principal of the 2023 Notes were
April 15, 2023, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day year consisting of
twelve 30-day months) at the Treasury Rate plus 20 basis points,


 


plus, in each case, any interest
accrued but not paid to, but excluding, the Redemption Date.


 


(g)            At any time on or after April 15,
2023, the 2023 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount of the
2023 Notes being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


(h)            At any time prior to March 15, 2026,
the 2026 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice by mail,
in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


(i)            100% of the principal
amount of the 2026 Notes being redeemed, or


 


(ii)            the sum of the present
value of (x) 100% of the principal amount of the 2026 Notes being redeemed and (y) all required remaining scheduled interest payments
due on the 2026 Notes being redeemed, in each case calculated as if the Stated Maturity of the principal of the 2026 Notes were
March 15, 2026, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day year consisting of
twelve 30-day months) at the Treasury Rate plus 25 basis points,


 


plus, in each case, any interest
accrued but not paid to, but excluding, the Redemption Date.


 




    15


     


    

(i)            At any time on or after March 15,
2026, the 2026 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount of the
2026 Notes being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


(j)            At any time prior to December 15,
2035, the 2036 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


(i)            100% of the principal
amount of the 2036 Notes being redeemed, or


 


(ii)            the sum of the present
value of (x) 100% of the principal amount of the 2036 Notes being redeemed and (y) all required remaining scheduled interest payments
due on the 2036 Notes being redeemed, in each case calculated as if the Stated Maturity of the principal of the 2036 Notes were
December 15, 2035, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day year consisting
of twelve 30-day months) at the Treasury Rate plus 30 basis points,


 


plus, in each case, any interest
accrued but not paid to, but excluding, the Redemption Date.


 


(k)            At any time on or after December
15, 2035, the 2036 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount of the
2036 Notes being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


(l)            At any time prior to December 15,
2045, the 2046 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


(i)            100% of the principal
amount of the 2046 Notes being redeemed, or


 


(ii)            the sum of the present
value of (x) 100% of the principal amount of the 2046 Notes being redeemed and (y) all required remaining scheduled interest payments
due on the 2046 Notes being redeemed, in each case calculated as if the Stated Maturity of the principal of the 2046 Notes were
December 15, 2045, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day year consisting
of twelve 30-day months) at the Treasury Rate plus 30 basis points,


 




    16


     


    

plus, in each case, any interest
accrued but not paid to, but excluding, the Redemption Date.


 


(m)            At any time on or after December
15, 2045, the 2046 Notes will be redeemable upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount of the
2046 Notes being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


(n)            Notice of any redemption will be
mailed at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each holder of the Notes of the
series to be redeemed.


 


(o)            Unless the Company defaults in payment
of the Redemption Price, interest will cease to accrue on the Notes of the series or the portions of the Notes of the series called
for redemption on and after the Redemption Date.


 


Section 2.07.            Special Mandatory Redemption.


 


(a)            If the Merger has not been completed
by December 31, 2016 (or such later date to which the End Date is extended by agreement between the Company and Humana pursuant
to the terms of the Merger Agreement) or if, prior to such date, the Merger Agreement is terminated, then the Company shall redeem
all of the Special Mandatory Redemption Notes on the Special Mandatory Redemption Date at a special mandatory redemption price
equal to 101% of the aggregate principal amount of the Special Mandatory Redemption Notes, plus accrued and unpaid interest from
the date of initial issuance, or the most recent date to which interest has been paid or provided for, whichever is later, to,
but excluding, the Special Mandatory Redemption Date. There is no special mandatory redemption of the Floating Rate Notes, the
2018 Notes or the 2023 Notes.


 


(b)            The Company shall cause notice of
a special mandatory redemption to be transmitted to each Holder of Special Mandatory Redemption Notes at its registered address,
with a copy to the Trustee, no later than 60 days after the occurrence of the event triggering the special mandatory redemption.
If funds sufficient to pay the special mandatory redemption price of the Special Mandatory Redemption Notes on the Special Mandatory
Redemption Date (plus accrued and unpaid interest, if any, to the Special Mandatory Redemption Date) are deposited with the Trustee
on or before such Special Mandatory Redemption Date, the Special Mandatory Redemption Notes will cease to bear interest on and
after the Special Mandatory Redemption Date.


 


Section 2.08.            Change of Control Offer
to Purchase.


 


(a)            If a Change of Control Triggering
Event occurs with respect to the Notes of a series, unless the Company has exercised its right, if any, to redeem the Notes of
such series in full pursuant to ‎‎Section 2.06 or the Company has redeemed,
or is required to redeem, the Notes of such series in full pursuant to a special mandatory redemption pursuant to ‎Section
2.07, the Company will make an offer to each Holder of Notes of


 




    17


     


    

such
series (the “Change of Control Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of
$1,000) of such Holder’s Notes of such series at a repurchase price in cash equal to 101% of the aggregate principal amount
of the Notes of such series to be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of
repurchase (the “Change of Control Payment”). Within 30 days following any Change of Control Triggering Event
with respect to the Notes of a series, the Company will mail a notice to Holders of the Notes of such series describing the transaction
or transactions that constitute the Change of Control Triggering Event and offering to repurchase the Notes of such series on
the date specified in the notice (the “Change of Control Payment Date”), which date will be no less than 30
days and no more than 60 days from the date such notice is mailed, pursuant to the procedures required by the Notes of such series
and described in such notice.


 


(b)            The Company will comply with the
requirements of Rule 14e-1 under the Exchange Act and any other securities laws and regulations thereunder to the extent those
laws and regulations are applicable in connection with the repurchase of the Notes of a series as a result of a Change of Control
Triggering Event. To the extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase
provisions of the Notes of a series, the Company will comply with the applicable securities laws and regulations and will not be
deemed to have breached its obligations under the Change of Control repurchase provisions of any Notes by virtue of such conflicts.


 


(c)            The Company will not be required
to offer to repurchase the Notes of a series upon the occurrence of a Change of Control Triggering Event with respect to the Notes
of such series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements
for an offer made by the Company, and the third party repurchases on the applicable date all Notes of such series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Notes of such series and the Indenture, a failure
by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure by the
Company to comply with its obligations to offer to purchase the Notes of such series unless the Company promptly makes an offer
to repurchase the Notes of such series at 101% of the outstanding principal amount thereof plus accrued and unpaid interest, if
any, thereon, to, but excluding, the date of repurchase, which shall be no later than 30 days after the third party’s scheduled
Change of Control Payment Date.


 


(d)            On the Change of Control Payment
Date for Notes of a series to be repurchased, the Company will, to the extent lawful:


 


(i)            accept or cause a third
party to accept for payment all Notes of such series or portions of Notes of such series properly tendered pursuant to the Change
of Control Offer;


 


(ii)            deposit or cause a third
party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect of all Notes of such series
or portions of Notes of such series properly tendered; and


 




    18


     


    

(iii)            deliver or cause to
be delivered to the Trustee the Notes of such series properly accepted, together with an officer’s certificate stating the
aggregate principal amount of Notes of such series or portions of Notes of such series being purchased.


 


Section 2.09.            Applicability of Certain
Provisions of the Base Indenture in Respect of the Notes.


 


(a)            The Event of Default specified in
Section 501(5) of the Base Indenture shall not apply to the Notes.


 


(b)            Section 1005 of the Base Indenture
shall not apply to the Notes.


 


(c)            The second line of Section 1104
of the Base Indenture is hereby amended to replace “30” with “15” for purposes of the Notes.


 


(d)            Section 704 of the Base Indenture
is hereby amended and restated to read in its entirety as follows: “The Company shall file with the Trustee and the Commission,
and transmit to Holders, such information, documents and other reports, and such summaries thereof, as may be required pursuant
to the Trust Indenture Act at the times and in the manner provided pursuant to the Trust Indenture Act; provided, however,
that any such information, document or report filed with the Commission on its Electronic Data Gathering, Analysis and Retrieval
(or EDGAR) system or any successor thereto shall be deemed to be filed with the Trustee.”


 


Section 2.10.            Registrar and Paying
Agent; Calculation Agent. U.S. Bank National Association shall act as Paying Agent and registrar with respect to the Notes.
The Calculation Agent for the Floating Rate Notes shall initially be U.S. Bank National Association, unless and until such time
as a successor is appointed. If that bank is unable or unwilling to continue to act as the Calculation Agent or if it fails to
calculate properly the interest rate on the Floating Rate Notes for any applicable Floating Rate Interest Period, the Company may
appoint another leading commercial or investment bank engaged in the London interbank market to act as Calculation Agent in its
place. The Calculation Agent may not resign its duties without a successor having been appointed.


 


Section 2.11.            No Sinking Fund. The
Company shall not be obligated to redeem or purchase the Notes of any series pursuant to any sinking fund or analogous provision,
or at the option of any Holder thereof, except as provided in Sections ‎2.07 or
‎2.08 of this Supplemental Indenture.


 


Section 2.12.            Minimum Denominations.
The Notes shall be issuable only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in
excess thereof.


 




    19


     


    

Article
3

Miscellaneous


 


Section 3.01.            Relation to Indenture.
This Supplemental Indenture shall form a part of the Indenture for all purposes, and every Holder of Securities heretofore
or hereafter authenticated and delivered under the Indenture shall be bound hereby.


 


Section 3.02.            Continued Effect. Except
as expressly supplemented and amended by this Supplemental Indenture, the Base Indenture shall continue in full force and effect
in accordance with the provisions thereof, and the Base Indenture is in all respects hereby ratified and confirmed. This Supplemental
Indenture and all its provisions shall be deemed a part of the Indenture in the manner and to the extent herein and therein provided.


 


Section 3.03.            Provisions Binding on
Company’s Successors. All of the covenants, stipulations, promises and agreements in this Supplemental Indenture by the
Company shall bind its successors and assigns whether so expressed or not.


 


Section 3.04.            Certain Trustee Matters.


 


(a)            The recitals contained herein shall
be taken as the statements of the Company, and the Trustee assumes no responsibility for their correctness.


 


(b)            The Trustee makes no representations
as to the validity or sufficiency of this Supplemental Indenture or the Notes or the proper authorization or the due execution
hereof or thereof by the Company.


 


Section 3.05.            Governing Law. This
Supplemental Indenture and the Notes shall be governed by and construed in accordance with the internal laws of the State of New
York.


 


Section 3.06.            Counterparts. This
Supplemental Indenture may be signed in various counterparts which together will constitute one and the same instrument.


 


[signatures follow]


 




    20


     


    

IN WITNESS WHEREOF, the parties hereto have
caused this Supplemental Indenture to be duly executed as of the date first above written.


 


	AETNA INC., as the Company


	 
	 
	 
	By:	/s/ David Buda
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer
	 	 	 
	 	 	 



	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	 
	By:	/s/ David J. Ganss
	 	Name:	David J. Ganss
	 	Title:	Vice President





     


     


    

 


Exhibit A


 

Form of Floating Rate Senior Note due 2017


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


FLOATING RATE SENIOR NOTE DUE 2017


 


CUSIP: 00817Y AR9

ISIN: US00817YAR99


 





	No. 2017-1	$          




 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of          
Dollars ($          ) upon presentation and surrender of this Security on December
8, 2017, and to pay interest thereon from June 9, 2016 or from the most recent Floating Rate Interest Payment Date to which interest
has been paid or duly provided for, quarterly on March 8, June 8, September 8 and December 8 in each year, beginning September
8, 2016, at a rate per annum equal to the Three-Month LIBOR as determined on the Floating Rate Interest Determination Date for
the applicable Floating Rate Interest Period, plus 0.650% as calculated by the Calculation Agent, until the principal hereof is
paid or made available for payment. The Calculation Agent has set the initial interest rate on this Security at 1.3066% per annum,
and will reset such interest rate for each Floating


 




    A-1


     


    

Rate
Interest Period on the Floating Rate Interest Payment Date for the preceding Floating Rate Interest Period. The interest so payable,
and punctually paid or duly provided for, on any Floating Rate Interest Payment Date will, as provided in such Indenture, be paid
to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the close of business on the
Floating Rate Regular Record Date for such interest, which shall be the February 21, May 24, August 24 or November 23 (whether
or not a Business Day), as the case may be, next preceding such Floating Rate Interest Payment Date. Any such interest not so
punctually paid or duly provided for will forthwith cease to be payable to the Holder on such Floating Rate Regular Record Date
and may either be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the
close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof
shall be given to Holders of Securities of this series not less than 10 calendar days prior to such Special Record Date,
or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the
Securities of this series may be listed, and upon such notice as may be required by such exchange, all as more fully provided
in such Indenture. In any case where any Floating Rate Interest Payment Date is not a Business Day, then payment of interest may
be made on the next succeeding Business Day without any additional amount being payable in respect of any delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    A-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 


	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer


[SEAL]


 


	Attest:
	 
	 
	
	Judith H. Jones




    A-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series designated under,
and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    A-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $500,000,000, subject to
future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, the Company will make an offer to each Holder of the Securities of this series
(the “Change of Control Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000)
of such Holder’s Securities of this series at a repurchase price in cash equal to 101% of the aggregate principal amount
of the Securities of this series to be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date
of repurchase (the “Change of Control Payment”). Within 30 days following any Change of Control Triggering Event
with respect to the Securities of this series, the Company will mail a notice to Holders of the Securities of this series describing
the transaction or transactions that constitute the Change of Control Triggering Event and offering to repurchase the Securities
of this series on the date specified in the notice (the “Change of Control Payment Date”), which date will be
no less than 30 days and no more than 60 days from the date such notice is mailed, pursuant to the procedures required hereby and
described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 




    A-R-5


     


    

The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure
by the Company to comply with its obligations to offer to purchase the Securities of this series unless the Company promptly makes
an offer to repurchase the Securities of this series at 101% of the outstanding principal amount thereof plus accrued and unpaid
interest, if any, thereon, to, but excluding, the date of repurchase, which shall be no later than 30 days after the third party’s
scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 


		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this


 




    A-R-6


     


    

series of Securities for purposes of the
definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to which this definition
would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s or the Trustee’s
request that the reduction was the result, in whole or in part, of any event or circumstance comprised of or arising as a result
of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control has occurred at the time
of the rating event).


 


“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly or indirectly,
of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however, that a
transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a holding
company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies”.


 


“Moody’s” means
Moody’s Investors Service, Inc.


 




    A-R-7


     


    

“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement rating agency for any of Moody’s, S&P or Fitch, or all of them, as the
case may be, with respect to the Securities of this series.


 


“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


2.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens on the Common Stock of Principal Subsidiaries set forth therein, does not apply to
the Securities of this series.


 


3.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


4.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 




    A-R-8


     


    

5.            Other Matters.


 


No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form
satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such Holder’s attorney duly
authorized in writing, and thereupon one or more new Securities of this series and of like tenor, of authorized denominations and
for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate
principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 




    A-R-9


     


    

No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,
or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 




    A-R-10


     


    




 


Exhibit B





Form of 1.700% Senior Note due 2018


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


1.700% SENIOR NOTE DUE 2018


 


CUSIP: 00817Y AS7

ISIN: US00817YAS72


 


	No. 2018-1	$          


 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of          
Dollars ($          ) upon presentation and surrender of this Security on June
7, 2018, and to pay interest thereon from June 9, 2016, or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, semi-annually on June 7 and December 7 in each year, beginning December 7, 2016, at the rate of 1.700%
per annum until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which
shall be the May 23 or November 22 (whether or


 




    B-1


     


    

not a Business Day), as the case may be,
next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith cease to
be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security (or one or
more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such Defaulted
Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than 10 calendar
days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements
of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be required by such
exchange, all as more fully provided in such Indenture. In any case where any Interest Payment Date is not a Business Day, then
payment of interest may be made on the next succeeding Business Day without any additional amount being payable in respect of any
delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    B-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 


	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer



 


 


 


 

	[SEAL]
	 
	 
	Attest:

         

         

         

	
	Judith H. Jones




    B-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series designated under,
and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    B-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $1,000,000,000, subject
to future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.            Optional Redemption.


 


At any time, the Securities of this series
are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’ notice by mail, in whole
or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


		·	100% of the principal amount of the Securities being redeemed, or



 


		·	the sum of the present value of (x) 100% of the principal amount of the Securities being redeemed and (y) all required remaining
scheduled interest payments due on the Securities being redeemed, discounted to, but excluding, the Redemption Date on a semi-annual
basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 15 basis points,



 


plus, in each case, any interest accrued
but not paid to, but excluding, the Redemption Date.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Securities of this series,


 


		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before



 




    B-R-1


     


    

or after the Remaining Life for the
Securities of this series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue
will be determined and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding
to the nearest month), or


 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Securities of this series to be redeemed, calculated as if the Stated Maturity of the principal
of such Securities were June 7, 2018 (the “Remaining Life” of such Securities) that would be utilized, at the
time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable
maturity to the Remaining Life of the Securities of this series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Securities of this series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 


“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


Notice of any redemption will be mailed
at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each Holder of the Securities of this


 




    B-R-2


     


    

series to be redeemed. The second line of
Section 1104 of the Base Indenture is amended to replace “30” with “15” for purposes of the Securities
of this series.


 


Unless the Company defaults in payment of
the Redemption Price, interest will cease to accrue on the Securities of this series or the portions of the Securities of this
series called for redemption on and after the Redemption Date.


 


If this Security is redeemed in part only,
a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.


 


2.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, unless the Company has exercised its right to redeem the Securities of this
series in full, the Company will make an offer to each Holder of the Securities of this series (the “Change of Control
Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000) of such Holder’s Securities
of this series at a repurchase price in cash equal to 101% of the aggregate principal amount of the Securities of this series to
be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase (the “Change
of Control Payment”). Within 30 days following any Change of Control Triggering Event with respect to the Securities
of this series, the Company will mail a notice to Holders of the Securities of this series describing the transaction or transactions
that constitute the Change of Control Triggering Event and offering to repurchase the Securities of this series on the date specified
in the notice (the “Change of Control Payment Date”), which date will be no less than 30 days and no more than
60 days from the date such notice is mailed, pursuant to the procedures required hereby and described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 


The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such


 




    B-R-3


     


    

offer and to complete such offer shall be
treated as a failure by the Company to comply with its obligations to offer to purchase the Securities of this series unless the
Company promptly makes an offer to repurchase the Securities of this series at 101% of the outstanding principal amount thereof
plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase, which shall be no later than 30 days
after the third party’s scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 


		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this series of Securities
for purposes of the definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to
which this definition would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s
or the Trustee’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of
or arising as a result of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control
has occurred at the time of the rating event).


 




    B-R-4


     


    

“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly or indirectly,
of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however, that a
transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a holding
company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies.”


 


“Moody’s” means
Moody’s Investors Service, Inc.


 


“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may
be, with respect to the Securities of this series.


 




    B-R-5


     


    

“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


3.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens on the Common Stock of Principal Subsidiaries set forth therein, does not apply to
the Securities of this series.


 


4.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


5.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 


6.            Other Matters.


 


No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly


 




    B-R-6


     


    

endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such
Holder’s attorney duly authorized in writing, and thereupon one or more new Securities of this series and of like tenor,
of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate
principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 


No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,
or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 




    B-R-7


     


    




 


Exhibit C





Form of 1.900% Senior Note due 2019


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


1.900% SENIOR NOTE DUE 2019


 


CUSIP: 00817Y AT5

ISIN: US00817YAT55


 


	No. 2019-1	$          


 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of           
Dollars ($          ) upon presentation and surrender of this Security on June
7, 2019, and to pay interest thereon from June 9, 2016, or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, semi-annually on June 7 and December 7 in each year, beginning December 7, 2016, at the rate of 1.900%
per annum until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which
shall be the May 23 or November 22 (whether or


 




    C-1


     


    

not a Business Day), as the case may be,
next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith cease to
be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security (or one or
more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such Defaulted
Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than 10 calendar
days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements
of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be required by such
exchange, all as more fully provided in such Indenture. In any case where any Interest Payment Date is not a Business Day, then
payment of interest may be made on the next succeeding Business Day without any additional amount being payable in respect of any
delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    C-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 





	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer



 


 


 


 

	[SEAL]
	 
	 
	Attest:

         

         

         

	
	Judith H. Jones




 




    C-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series designated under,
and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    C-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $1,650,000,000, subject
to future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.            Optional Redemption.


 


At any time, the Securities of this series
are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’ notice by mail, in whole
or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


		·	100% of the principal amount of the Securities being redeemed, or



 


		·	the sum of the present value of (x) 100% of the principal amount of the Securities being redeemed and (y) all required remaining
scheduled interest payments due on the Securities being redeemed, discounted to, but excluding, the Redemption Date on a semi-annual
basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 15 basis points,



 


plus, in each case, any interest accrued
but not paid to, but excluding, the Redemption Date.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Securities of this series,


 


		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before



 




    C-R-1


     


    

or after the Remaining Life for the
Securities of this series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue
will be determined and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding
to the nearest month), or


 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Securities of this series to be redeemed, calculated as if the Stated Maturity of the principal
of such Securities were June 7, 2019 (the “Remaining Life” of such Securities) that would be utilized, at the
time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable
maturity to the Remaining Life of the Securities of this series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Securities of this series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 


“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


Notice of any redemption will be mailed
at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each Holder of the Securities of this


 




    C-R-2


     


    

series to be redeemed. The second line of
Section 1104 of the Base Indenture is amended to replace “30” with “15” for purposes of the Securities
of this series.


 


Unless the Company defaults in payment of
the Redemption Price, interest will cease to accrue on the Securities of this series or the portions of the Securities of this
series called for redemption on and after the Redemption Date.


 


If this Security is redeemed in part only,
a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.


 


2.            Special Mandatory Redemption.


 


If the Merger has not been completed by
December 31, 2016 (or such later date to which the End Date is extended by agreement between the Company and Humana pursuant to
the terms of the Merger Agreement) or if, prior to such date, the Merger Agreement is terminated, then the Company shall redeem
all of the Securities of this series on the Special Mandatory Redemption Date at a special mandatory redemption price equal to
101% of the aggregate principal amount of such Securities, plus accrued and unpaid interest from the date of initial issuance,
or the most recent date to which interest has been paid or provided for, whichever is later, to, but excluding, the Special Mandatory
Redemption Date.


 


The Company shall cause notice of a special
mandatory redemption to be transmitted to each Holder of the Securities of this series at its registered address, with a copy to
the Trustee, no later than 60 days after the occurrence of the event triggering the special mandatory redemption. If funds sufficient
to pay the special mandatory redemption price of the Securities of this series on the Special Mandatory Redemption Date (plus accrued
and unpaid interest, if any, to the Special Mandatory Redemption Date) are deposited with the Trustee on or before such Special
Mandatory Redemption Date, the Securities of this series will cease to bear interest on and after the Special Mandatory Redemption
Date.


 


“End Date” has the meaning
ascribed to such term in the Merger Agreement.


 


“Humana” means Humana
Inc., a Delaware corporation.


 


“Merger” means the acquisition
of Humana by the Company on the terms and subject to the conditions set forth in the Merger Agreement.


 


“Merger Agreement” means
the Agreement and Plan of Merger, dated as of July 2, 2015, among the Company, Echo Merger Sub, Inc., Echo Merger Sub, LLC and
Humana, as amended from time to time.


 


“Special Mandatory Redemption Date”
means the 30th day (or if such day is not a Business Day, the first Business Day thereafter) following the transmission of a notice
of special mandatory redemption.


 




    C-R-3


     


    

3.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, unless the Company has exercised its right to redeem the Securities of this
series in full or the Company has redeemed, or is required to redeem, the Securities of this series in full pursuant to Section
2 of this Security, the Company will make an offer to each Holder of the Securities of this series (the “Change of Control
Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000) of such Holder’s Securities
of this series at a repurchase price in cash equal to 101% of the aggregate principal amount of the Securities of this series to
be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase (the “Change
of Control Payment”). Within 30 days following any Change of Control Triggering Event with respect to the Securities
of this series, the Company will mail a notice to Holders of the Securities of this series describing the transaction or transactions
that constitute the Change of Control Triggering Event and offering to repurchase the Securities of this series on the date specified
in the notice (the “Change of Control Payment Date”), which date will be no less than 30 days and no more than
60 days from the date such notice is mailed, pursuant to the procedures required hereby and described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 


The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure
by the Company to comply with its obligations to offer to purchase the Securities of this series unless the Company promptly makes
an offer to repurchase the Securities of this series at 101% of the outstanding principal amount thereof plus accrued and unpaid
interest, if any, thereon, to, but excluding, the date of repurchase, which shall be no later than 30 days after the third party’s
scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 




    C-R-4


     


    

		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this series of Securities
for purposes of the definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to
which this definition would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s
or the Trustee’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of
or arising as a result of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control
has occurred at the time of the rating event).


 


“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of


 




    C-R-5


     


    

its subsidiaries becomes the beneficial
owner, directly or indirectly, of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided,
however, that a transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary
of a holding company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction
are substantially the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately
following that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial
owner, directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies.”


 


“Moody’s” means
Moody’s Investors Service, Inc.


 


“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may
be, with respect to the Securities of this series.


 


“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


4.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens


 




    C-R-6


     


    

on
the Common Stock of Principal Subsidiaries set forth therein, does not apply to the Securities of this series.


 


5.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


6.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 


7.            Other Matters.


 


No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form
satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such Holder’s attorney duly
authorized in writing, and thereupon one or more new Securities of this series and of like tenor, of authorized denominations and
for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series


 




    C-R-7


     


    

are
exchangeable for a like aggregate principal amount of Securities of this series and of like tenor of a different authorized denomination,
as requested by the Holder surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 


No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,
or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 




    C-R-8


     


    




 


Exhibit D





Form of 2.400% Senior Note due 2021


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


2.400% SENIOR NOTE DUE 2021


 


CUSIP: 00817Y AU2

ISIN: US00817YAU29


 


	No. 2021-1	$          


 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of          Dollars
($          ) upon presentation and surrender of this Security on June 15, 2021,
and to pay interest thereon from June 9, 2016, or from the most recent Interest Payment Date to which interest has been paid or
duly provided for, semi-annually on June 15 and December 15 in each year, beginning December 15, 2016 at the rate of 2.400% per
annum until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly provided
for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security (or one
or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which shall
be the June 1 or December 1


 




    D-1


     


    

(whether or not a Business Day), as the
case may be, next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith
cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such
Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than
10 calendar days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with
the requirements of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be
required by such exchange, all as more fully provided in such Indenture. In any case where any Interest Payment Date is not a Business
Day, then payment of interest may be made on the next succeeding Business Day without any additional amount being payable in respect
of any delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    D-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 





	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer



 


 


 


 

	[SEAL]
	 
	 
	Attest:

         

         

         

	
	Judith H. Jones




 




    D-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series
designated under, and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    D-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $1,850,000,000, subject
to future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.            Optional Redemption.


 


At any time prior to May 15, 2021, the Securities
of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’ notice
by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


		·	100% of the principal amount of the Securities being redeemed, or



 


		·	the sum of the present value of (x) 100% of the principal amount of the Securities being redeemed and (y) all required remaining
scheduled interest payments due on the Securities being redeemed, in each case calculated as if the Stated Maturity of the principal
of such Securities were May 15, 2021, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day
year consisting of twelve 30-day months) at the Treasury Rate plus 20 basis points,



 


plus, in each case, any interest accrued
but not paid to, but excluding, the Redemption Date.


 


At any time on or after May 15, 2021, the
Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount
of the Securities being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Securities of this series,


 




    D-R-1


     


    

		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before or after the Remaining Life for the Securities of this
series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined
and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding to the nearest
month), or



 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Securities of this series to be redeemed, calculated as if the Stated Maturity of the principal
of such Securities were May 15, 2021 (the “Remaining Life” of such Securities) that would be utilized, at the
time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable
maturity to the Remaining Life of the Securities of this series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Securities of this series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 




    D-R-2


     


    

“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


Notice of any redemption will be mailed
at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each Holder of the Securities of this
series to be redeemed. The second line of Section 1104 of the Base Indenture is amended to replace “30” with “15”
for purposes of the Securities of this series.


 


Unless the Company defaults in payment of
the Redemption Price, interest will cease to accrue on the Securities of this series or the portions of the Securities of this
series called for redemption on and after the Redemption Date.


 


If this Security is redeemed in part only,
a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.


 


2.            Special Mandatory Redemption.


 


If the Merger has not been completed by
December 31, 2016 (or such later date to which the End Date is extended by agreement between the Company and Humana pursuant to
the terms of the Merger Agreement) or if, prior to such date, the Merger Agreement is terminated, then the Company shall redeem
all of the Securities of this series on the Special Mandatory Redemption Date at a special mandatory redemption price equal to
101% of the aggregate principal amount of such Securities, plus accrued and unpaid interest from the date of initial issuance,
or the most recent date to which interest has been paid or provided for, whichever is later, to, but excluding, the Special Mandatory
Redemption Date.


 


The Company shall cause notice of a special
mandatory redemption to be transmitted to each Holder of the Securities of this series at its registered address, with a copy to
the Trustee, no later than 60 days after the occurrence of the event triggering the special mandatory redemption. If funds sufficient
to pay the special mandatory redemption price of the Securities of this series on the Special Mandatory Redemption Date (plus accrued
and unpaid interest, if any, to the Special Mandatory Redemption Date) are deposited with the Trustee on or before such Special
Mandatory Redemption Date, the Securities of this series will cease to bear interest on and after the Special Mandatory Redemption
Date.


 


“End Date” has the meaning
ascribed to such term in the Merger Agreement.


 


“Humana” means Humana
Inc., a Delaware corporation.


 


“Merger” means the acquisition
of Humana by the Company on the terms and subject to the conditions set forth in the Merger Agreement.


 




    D-R-3


     


    

“Merger Agreement” means
the Agreement and Plan of Merger, dated as of July 2, 2015, among the Company, Echo Merger Sub, Inc., Echo Merger Sub, LLC and
Humana, as amended from time to time.


 


“Special Mandatory Redemption Date”
means the 30th day (or if such day is not a Business Day, the first Business Day thereafter) following the transmission of a notice
of special mandatory redemption.


 


3.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, unless the Company has exercised its right to redeem the Securities of this
series in full or the Company has redeemed, or is required to redeem, the Securities of this series in full pursuant to Section
2 of this Security, the Company will make an offer to each Holder of the Securities of this series (the “Change of Control
Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000) of such Holder’s Securities
of this series at a repurchase price in cash equal to 101% of the aggregate principal amount of the Securities of this series to
be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase (the “Change
of Control Payment”). Within 30 days following any Change of Control Triggering Event with respect to the Securities
of this series, the Company will mail a notice to Holders of the Securities of this series describing the transaction or transactions
that constitute the Change of Control Triggering Event and offering to repurchase the Securities of this series on the date specified
in the notice (the “Change of Control Payment Date”), which date will be no less than 30 days and no more than
60 days from the date such notice is mailed, pursuant to the procedures required hereby and described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 


The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure
by the Company to comply


 




    D-R-4


     


    

with its obligations to offer to purchase
the Securities of this series unless the Company promptly makes an offer to repurchase the Securities of this series at 101% of
the outstanding principal amount thereof plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase,
which shall be no later than 30 days after the third party’s scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 


		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this series of Securities
for purposes of the definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to
which this definition would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s
or the Trustee’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of
or arising as a result of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control
has occurred at the time of the rating event).


 




    D-R-5


     


    

“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly or indirectly,
of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however, that a
transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a holding
company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies.”


 


“Moody’s” means
Moody’s Investors Service, Inc.


 


“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may
be, with respect to the Securities of this series.


 




    D-R-6


     


    

“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


4.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens on the Common Stock of Principal Subsidiaries set forth therein, does not apply to
the Securities of this series.


 


5.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


6.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 


7.            Other Matters.


 


No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly


 




    D-R-7


     


    

endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such
Holder’s attorney duly authorized in writing, and thereupon one or more new Securities of this series and of like tenor,
of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate
principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 


No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,
or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 




    D-R-8


     


    




 


Exhibit E





Form of 2.800% Senior Note due 2023


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


2.800% SENIOR NOTE DUE 2023


 


CUSIP: 00817Y AV0

ISIN: US00817YAV02


 


	No. 2023-1	$          


 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of          
Dollars ($          ) upon presentation and surrender of this Security on June
15, 2023, and to pay interest thereon from June 9, 2016, or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, semi-annually on June 15 and December 15 in each year, beginning December 15, 2016, at the rate of 2.800%
per annum until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which
shall be the June 1 or December 1


 




    E-1


     


    

(whether or not a Business Day), as the
case may be, next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith
cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such
Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than
10 calendar days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with
the requirements of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be
required by such exchange, all as more fully provided in such Indenture. In any case where any Interest Payment Date is not a Business
Day, then payment of interest may be made on the next succeeding Business Day without any additional amount being payable in respect
of any delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    E-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 








	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer



 


 


 


 

	[SEAL]
	 
	 
	Attest:

         

         

         

	
	Judith H. Jones




 



 




    E-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series
designated under, and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    E-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $1,300,000,000, subject
to future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.             Optional Redemption.


 


At any time prior to April 15, 2023, the
Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


		·	100% of the principal amount of the Securities being redeemed, or



 


		·	the sum of the present value of (x) 100% of the principal amount of the Securities being redeemed and (y) all required remaining
scheduled interest payments due on the Securities being redeemed, in each case calculated as if the Stated Maturity of the principal
of such Securities were April 15, 2023, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day
year consisting of twelve 30-day months) at the Treasury Rate plus 20 basis points,



 


plus, in each case, any interest accrued
but not paid to, but excluding, the Redemption Date.


 


At any time on or after April 15, 2023,
the Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount
of the Securities being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Securities of this series,


 




    E-R-1


     


    

		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before or after the Remaining Life for the Securities of this
series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined
and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding to the nearest
month), or



 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Securities of this series to be redeemed, calculated as if the Stated Maturity of the principal
of such Securities were April 15, 2023 (the “Remaining Life” of such Securities) that would be utilized, at
the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of
comparable maturity to the Remaining Life of the Securities of this series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Securities of this series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 




    E-R-2


     


    

“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


Notice of any redemption will be mailed
at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each Holder of the Securities of this
series to be redeemed. The second line of Section 1104 of the Base Indenture is amended to replace “30” with “15”
for purposes of the Securities of this series.


 


Unless the Company defaults in payment of
the Redemption Price, interest will cease to accrue on the Securities of this series or the portions of the Securities of this
series called for redemption on and after the Redemption Date.


 


If this Security is redeemed in part only,
a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.


 


2.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, unless the Company has exercised its right to redeem the Securities of this
series in full, the Company will make an offer to each Holder of the Securities of this series (the “Change of Control
Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000) of such Holder’s Securities
of this series at a repurchase price in cash equal to 101% of the aggregate principal amount of the Securities of this series to
be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase (the “Change
of Control Payment”). Within 30 days following any Change of Control Triggering Event with respect to the Securities
of this series, the Company will mail a notice to Holders of the Securities of this series describing the transaction or transactions
that constitute the Change of Control Triggering Event and offering to repurchase the Securities of this series on the date specified
in the notice (the “Change of Control Payment Date”), which date will be no less than 30 days and no more than
60 days from the date such notice is mailed, pursuant to the procedures required hereby and described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 




    E-R-3


     


    

The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure
by the Company to comply with its obligations to offer to purchase the Securities of this series unless the Company promptly makes
an offer to repurchase the Securities of this series at 101% of the outstanding principal amount thereof plus accrued and unpaid
interest, if any, thereon, to, but excluding, the date of repurchase, which shall be no later than 30 days after the third party’s
scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 


		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this


 




    E-R-4


     


    

series of Securities for purposes of the
definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to which this definition
would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s or the Trustee’s
request that the reduction was the result, in whole or in part, of any event or circumstance comprised of or arising as a result
of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control has occurred at the time
of the rating event).


 


“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly or indirectly,
of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however, that a
transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a holding
company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies.”


 


“Moody’s” means
Moody’s Investors Service, Inc.


 




    E-R-5


     


    

“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may
be, with respect to the Securities of this series.


 


“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


3.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens on the Common Stock of Principal Subsidiaries set forth therein, does not apply to
the Securities of this series.


 


4.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


5.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 


6.            Other Matters.


 




    E-R-6


     


    

No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form
satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such Holder’s attorney duly
authorized in writing, and thereupon one or more new Securities of this series and of like tenor, of authorized denominations and
for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate
principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 


No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,


 




    E-R-7


     


    

or
based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 




    E-R-8


     


    




 


Exhibit F





Form of 3.200% Senior Note due 2026


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


3.200% SENIOR NOTE DUE 2026


 


CUSIP: 00817Y AW8

ISIN: US00817YAW84


 


	No. 2026-1	$          


 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of          
Dollars ($          ) upon presentation and surrender of this Security on June
15, 2026, and to pay interest thereon from June 9, 2016, or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, semi-annually on June 15 and December 15 in each year, beginning December 15, 2016, at the rate of 3.200%
per annum until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which
shall be the June 1 or December 1


 




    F-1


     


    

(whether or not a Business Day), as the
case may be, next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith
cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such
Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than
10 calendar days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with
the requirements of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be
required by such exchange, all as more fully provided in such Indenture. In any case where any Interest Payment Date is not a Business
Day, then payment of interest may be made on the next succeeding Business Day without any additional amount being payable in respect
of any delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    F-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 


 








	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer



 


 


 


 

	[SEAL]
	 
	 
	Attest:

         

         

         

	
	Judith H. Jones




 





    F-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series designated under,
and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    F-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $2,800,000,000, subject
to future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.            Optional Redemption.


 


At any time prior to March 15, 2026, the
Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


		·	100% of the principal amount of the Securities being redeemed, or



 


		·	the sum of the present value of (x) 100% of the principal amount of the Securities being redeemed and (y) all required remaining
scheduled interest payments due on the Securities being redeemed, in each case calculated as if the Stated Maturity of the principal
of such Securities were March 15, 2026, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a 360-day
year consisting of twelve 30-day months) at the Treasury Rate plus 25 basis points,



 


plus, in each case, any interest accrued
but not paid to, but excluding, the Redemption Date.


 


At any time on or after March 15, 2026,
the Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount
of the Securities being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Securities of this series,


 




    F-R-1


     


    

		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before or after the Remaining Life for the Securities of this
series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined
and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding to the nearest
month), or



 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Securities of this series to be redeemed, calculated as if the Stated Maturity of the principal
of such Securities were March 15, 2026 (the “Remaining Life” of such Securities) that would be utilized, at
the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of
comparable maturity to the Remaining Life of the Securities of this series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Securities of this series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 




    F-R-2


     


    

“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


Notice of any redemption will be mailed
at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each Holder of the Securities of this
series to be redeemed. The second line of Section 1104 of the Base Indenture is amended to replace “30” with “15”
for purposes of the Securities of this series.


 


Unless the Company defaults in payment of
the Redemption Price, interest will cease to accrue on the Securities of this series or the portions of the Securities of this
series called for redemption on and after the Redemption Date.


 


If this Security is redeemed in part only,
a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.


 


2.            Special Mandatory Redemption.


 


If the Merger has not been completed by
December 31, 2016 (or such later date to which the End Date is extended by agreement between the Company and Humana pursuant to
the terms of the Merger Agreement) or if, prior to such date, the Merger Agreement is terminated, then the Company shall redeem
all of the Securities of this series on the Special Mandatory Redemption Date at a special mandatory redemption price equal to
101% of the aggregate principal amount of such Securities, plus accrued and unpaid interest from the date of initial issuance,
or the most recent date to which interest has been paid or provided for, whichever is later, to, but excluding, the Special Mandatory
Redemption Date.


 


The Company shall cause notice of a special
mandatory redemption to be transmitted to each Holder of the Securities of this series at its registered address, with a copy to
the Trustee, no later than 60 days after the occurrence of the event triggering the special mandatory redemption. If funds sufficient
to pay the special mandatory redemption price of the Securities of this series on the Special Mandatory Redemption Date (plus accrued
and unpaid interest, if any, to the Special Mandatory Redemption Date) are deposited with the Trustee on or before such Special
Mandatory Redemption Date, the Securities of this series will cease to bear interest on and after the Special Mandatory Redemption
Date.


 


“End Date” has the meaning
ascribed to such term in the Merger Agreement.


 


“Humana” means Humana
Inc., a Delaware corporation.


 


“Merger” means the acquisition
of Humana by the Company on the terms and subject to the conditions set forth in the Merger Agreement.


 




    F-R-3


     


    

“Merger Agreement” means
the Agreement and Plan of Merger, dated as of July 2, 2015, among the Company, Echo Merger Sub, Inc., Echo Merger Sub, LLC and
Humana, as amended from time to time.


 


“Special Mandatory Redemption Date”
means the 30th day (or if such day is not a Business Day, the first Business Day thereafter) following the transmission of a notice
of special mandatory redemption.


 


3.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, unless the Company has exercised its right to redeem the Securities of this
series in full or the Company has redeemed, or is required to redeem, the Securities of this series in full pursuant to Section
2 of this Security, the Company will make an offer to each Holder of the Securities of this series (the “Change of Control
Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000) of such Holder’s Securities
of this series at a repurchase price in cash equal to 101% of the aggregate principal amount of the Securities of this series to
be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase (the “Change
of Control Payment”). Within 30 days following any Change of Control Triggering Event with respect to the Securities
of this series, the Company will mail a notice to Holders of the Securities of this series describing the transaction or transactions
that constitute the Change of Control Triggering Event and offering to repurchase the Securities of this series on the date specified
in the notice (the “Change of Control Payment Date”), which date will be no less than 30 days and no more than
60 days from the date such notice is mailed, pursuant to the procedures required hereby and described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 


The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure
by the Company to comply


 




    F-R-4


     


    

with its obligations to offer to purchase
the Securities of this series unless the Company promptly makes an offer to repurchase the Securities of this series at 101% of
the outstanding principal amount thereof plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase,
which shall be no later than 30 days after the third party’s scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 


		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this series of Securities
for purposes of the definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to
which this definition would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s
or the Trustee’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of
or arising as a result of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control
has occurred at the time of the rating event).


 




    F-R-5


     


    

“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly or indirectly,
of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however, that a
transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a holding
company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies.”


 


“Moody’s” means
Moody’s Investors Service, Inc.


 


“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may
be, with respect to the Securities of this series.


 




    F-R-6


     


    

“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


4.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens on the Common Stock of Principal Subsidiaries set forth therein, does not apply to
the Securities of this series.


 


5.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


6.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 


7.            Other Matters.


 


No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly


 




    F-R-7


     


    

endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such
Holder’s attorney duly authorized in writing, and thereupon one or more new Securities of this series and of like tenor,
of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate
principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 


No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,
or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 




    F-R-8


     


    




 


Exhibit G





Form of 4.250% Senior Note due 2036


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


4.250% SENIOR NOTE DUE 2036


 


CUSIP: 00817Y AY4

ISIN: US00817YAY41


 


	No. 2036-1	$          


 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of          
Dollars ($          ) upon presentation and surrender of this Security on June
15, 2036, and to pay interest thereon from June 9, 2016, or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, semi-annually on June 15 and December 15 in each year, beginning December 15, 2016, at the rate of 4.250%
per annum until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which
shall be the June 1 or December 1


 




    G-1


     


    

(whether or not a Business Day), as the
case may be, next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith
cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such
Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than
10 calendar days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with
the requirements of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be
required by such exchange, all as more fully provided in such Indenture. In any case where any Interest Payment Date is not a Business
Day, then payment of interest may be made on the next succeeding Business Day without any additional amount being payable in respect
of any delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    G-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 








	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer



 


 


 


 

	[SEAL]
	 
	 
	Attest:

         

         

         

	
	Judith H. Jones




 



 




    G-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series designated under,
and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    G-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $1,500,000,000, subject
to future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.            Optional Redemption.


 


At any time prior to December 15, 2035,
the Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


		·	100% of the principal amount of the Securities being redeemed, or



 


		·	the sum of the present value of (x) 100% of the principal amount of the Securities being redeemed and (y) all required remaining
scheduled interest payments due on the Securities being redeemed, in each case calculated as if the Stated Maturity of the principal
of such Securities were December 15, 2035, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a
360-day year consisting of twelve 30-day months) at the Treasury Rate plus 30 basis points,



 


plus, in each case, any interest accrued
but not paid to, but excluding, the Redemption Date.


 


At any time on or after December 15, 2035,
the Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount
of the Securities being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Securities of this series,


 




    G-R-1


     


    

		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before or after the Remaining Life for the Securities of this
series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined
and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding to the nearest
month), or



 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Securities of this series to be redeemed, calculated as if the Stated Maturity of the principal
of such Securities were December 15, 2035 (the “Remaining Life” of such Securities) that would be utilized,
at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities
of comparable maturity to the Remaining Life of the Securities of this series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Securities of this series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 




    G-R-2


     


    

“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


Notice of any redemption will be mailed
at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each Holder of the Securities of this
series to be redeemed. The second line of Section 1104 of the Base Indenture is amended to replace “30” with “15”
for purposes of the Securities of this series.


 


Unless the Company defaults in payment of
the Redemption Price, interest will cease to accrue on the Securities of this series or the portions of the Securities of this
series called for redemption on and after the Redemption Date.


 


If this Security is redeemed in part only,
a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.


 


2.            Special Mandatory Redemption.


 


If the Merger has not been completed by
December 31, 2016 (or such later date to which the End Date is extended by agreement between the Company and Humana pursuant to
the terms of the Merger Agreement) or if, prior to such date, the Merger Agreement is terminated, then the Company shall redeem
all of the Securities of this series on the Special Mandatory Redemption Date at a special mandatory redemption price equal to
101% of the aggregate principal amount of such Securities, plus accrued and unpaid interest from the date of initial issuance,
or the most recent date to which interest has been paid or provided for, whichever is later, to, but excluding, the Special Mandatory
Redemption Date.


 


The Company shall cause notice of a special
mandatory redemption to be transmitted to each Holder of the Securities of this series at its registered address, with a copy to
the Trustee, no later than 60 days after the occurrence of the event triggering the special mandatory redemption. If funds sufficient
to pay the special mandatory redemption price of the Securities of this series on the Special Mandatory Redemption Date (plus accrued
and unpaid interest, if any, to the Special Mandatory Redemption Date) are deposited with the Trustee on or before such Special
Mandatory Redemption Date, the Securities of this series will cease to bear interest on and after the Special Mandatory Redemption
Date.


 


“End Date” has the meaning
ascribed to such term in the Merger Agreement.


 


“Humana” means Humana
Inc., a Delaware corporation.


 


“Merger” means the acquisition
of Humana by the Company on the terms and subject to the conditions set forth in the Merger Agreement.


 




    G-R-3


     


    

“Merger Agreement” means
the Agreement and Plan of Merger, dated as of July 2, 2015, among the Company, Echo Merger Sub, Inc., Echo Merger Sub, LLC and
Humana, as amended from time to time.


 


“Special Mandatory Redemption Date”
means the 30th day (or if such day is not a Business Day, the first Business Day thereafter) following the transmission of a notice
of special mandatory redemption.


 


3.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, unless the Company has exercised its right to redeem the Securities of this
series in full or the Company has redeemed, or is required to redeem, the Securities of this series in full pursuant to Section
2 of this Security, the Company will make an offer to each Holder of the Securities of this series (the “Change of Control
Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000) of such Holder’s Securities
of this series at a repurchase price in cash equal to 101% of the aggregate principal amount of the Securities of this series to
be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase (the “Change
of Control Payment”). Within 30 days following any Change of Control Triggering Event with respect to the Securities
of this series, the Company will mail a notice to Holders of the Securities of this series describing the transaction or transactions
that constitute the Change of Control Triggering Event and offering to repurchase the Securities of this series on the date specified
in the notice (the “Change of Control Payment Date”), which date will be no less than 30 days and no more than
60 days from the date such notice is mailed, pursuant to the procedures required hereby and described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 


The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure
by the Company to comply


 




    G-R-4


     


    

with its obligations to offer to purchase
the Securities of this series unless the Company promptly makes an offer to repurchase the Securities of this series at 101% of
the outstanding principal amount thereof plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase,
which shall be no later than 30 days after the third party’s scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 


		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this series of Securities
for purposes of the definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to
which this definition would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s
or the Trustee’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of
or arising as a result of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control
has occurred at the time of the rating event).


 




    G-R-5


     


    

“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly or indirectly,
of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however, that a
transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a holding
company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies.”


 


“Moody’s” means
Moody’s Investors Service, Inc.


 


“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may
be, with respect to the Securities of this series.


 




    G-R-6


     


    

“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


4.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens on the Common Stock of Principal Subsidiaries set forth therein, does not apply to
the Securities of this series.


 


5.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


6.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 


7.            Other Matters.


 


No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly


 




    G-R-7


     


    

endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such
Holder’s attorney duly authorized in writing, and thereupon one or more new Securities of this series and of like tenor,
of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate
principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 


No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,
or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 




    G-R-8


     


    

 


Exhibit H





Form of 4.375% Senior Note due 2046


 


THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
TRANSFERRED TO, OR REGISTERED OR EXCHANGED FOR SECURITIES REGISTERED IN THE NAME OF, ANY PERSON OTHER THAN THE DEPOSITARY OR A
NOMINEE THEREOF, AND NO SUCH TRANSFER MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE. EVERY SECURITY
AUTHENTICATED AND DELIVERED UPON REGISTRATION OF TRANSFER OF, OR IN EXCHANGE FOR OR IN LIEU OF, THIS SECURITY SHALL BE A GLOBAL
SECURITY SUBJECT TO THE FOREGOING, EXCEPT IN SUCH LIMITED CIRCUMSTANCES.


 


Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation (“DTC”), to Aetna Inc. or its agent for registration
of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name
as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is
requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


 


AETNA INC.


 


4.375% SENIOR NOTE DUE 2046


 


CUSIP: 00817Y AX6

ISIN: US00817YAX67


 


	No. 2046-1	$          


 


AETNA INC., a Pennsylvania corporation (herein
called the “Company”), which term includes any successor Person under the Indenture hereinafter referred to,
for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of          
Dollars ($          ) upon presentation and surrender of this Security on June
15, 2046, and to pay interest thereon from June 9, 2016, or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, semi-annually on June 15 and December 15 in each year, beginning December 15, 2016, at the rate of 4.375%
per annum until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which
shall be the June 1 or December 1


 




    H-1


     


    

(whether or not a Business Day), as the
case may be, next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith
cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such
Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than
10 calendar days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with
the requirements of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be
required by such exchange, all as more fully provided in such Indenture. In any case where any Interest Payment Date is not a Business
Day, then payment of interest may be made on the next succeeding Business Day without any additional amount being payable in respect
of any delay.


 


Payment of the principal of and premium,
if any, and interest on this Security will be made at the office or agency of the Company maintained for that purpose in the United
States of America, in such coin or currency of the United States of America as at the time of payment is legal tender for payment
of public and private debts.


 


Reference is hereby made to the further
provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect
as if set forth at this place. Such provisions include, without limitation, provisions relating to redemption of this Security
by the Company.


 


Unless the certificate of authentication
hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled
to any benefit under such Indenture or be valid or obligatory for any purpose.


 




    H-2


     


    

IN WITNESS WHEREOF, the Company has caused
this instrument to be duly executed under its corporate seal.


 


Dated: June 9, 2016


 








	AETNA INC.
	 
	 
	By:	 
	 	Name:	David Buda
	 	Title:	Vice President, Finance and Treasurer



 


 


 


 

	[SEAL]
	 
	 
	Attest:

         

         

         

	
	Judith H. Jones




 



 




    H-3


     


    

TRUSTEE’S CERTIFICATE OF AUTHENTICATION


 


This is one of the Securities of the series designated under,
and referred to in, the within-mentioned Indenture.


 


	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	 
	 
	By:	 
	 	Authorized Officer





    H-4


     


    

(Back of Security)


 


This Security is one of a duly authorized
issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more
series under a Senior Indenture, dated as of March 2, 2001 (herein called the “Base Indenture”), between
the Company, as issuer, and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as
Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), as supplemented
by the Supplemental Indenture dated as of June 9, 2016, between the Company and the Trustee (together with the Base Indenture,
the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the
Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security
is one of the series designated on the face hereof, initially limited in aggregate principal amount to $2,400,000,000, subject
to future issuances of additional Securities pursuant to Section 301 of the Base Indenture.


 


1.            Optional Redemption.


 


At any time prior to December 15, 2045,
the Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to the greater of:


 


		·	100% of the principal amount of the Securities being redeemed, or



 


		·	the sum of the present value of (x) 100% of the principal amount of the Securities being redeemed and (y) all required remaining
scheduled interest payments due on the Securities being redeemed, in each case calculated as if the Stated Maturity of the principal
of such Securities were December 15, 2045, discounted to, but excluding, the Redemption Date on a semi-annual basis (assuming a
360-day year consisting of twelve 30-day months) at the Treasury Rate plus 30 basis points,



 


plus, in each case, any interest accrued
but not paid to, but excluding, the Redemption Date.


 


At any time on or after December 15, 2045,
the Securities of this series are subject to redemption upon not less than 15 calendar days’ nor more than 60 calendar days’
notice by mail, in whole or in part, at the election of the Company, at a Redemption Price equal to 100% of the principal amount
of the Securities being redeemed plus any interest accrued but not paid to, but excluding, the Redemption Date.


 


“Treasury Rate” means,
with respect to any Redemption Date for any portion of the Securities of this series,


 




    H-R-1


     


    

		·	the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently
published statistical release designated “H.15(519)” or any successor publication which is published weekly by the
Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities
adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the
Comparable Treasury Issue (if no maturity is within three months before or after the Remaining Life for the Securities of this
series, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined
and the Treasury Rate shall be interpolated or extrapolated from those yields on a straight line basis, rounding to the nearest
month), or



 


		·	if the release referred to in the previous bullet (or any successor release) is not published during the week preceding the
calculation date or does not contain the yields referred to above, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage
of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.



 


The Treasury Rate will be calculated on
the third Business Day preceding the Redemption Date.


 


“Comparable Treasury Issue”
means the United States Treasury security selected by an Independent Investment Banker as having an actual or interpolated maturity
comparable to the remaining term of the Securities of this series to be redeemed, calculated as if the Stated Maturity of the principal
of such Securities were December 15, 2045 (the “Remaining Life” of such Securities) that would be utilized,
at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities
of comparable maturity to the Remaining Life of the Securities of this series to be redeemed.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date for any Securities of this series, the average of all Reference Treasury Dealer Quotations
obtained.


 


“Independent Investment Banker”
means one of the Reference Treasury Dealers appointed by the Company.


 


“Reference Treasury Dealer”
means each of Citigroup Global Markets Inc. and UBS Securities LLC. If any Reference Treasury Dealer ceases to be a primary U.S.
government securities dealer in the United States (a “Primary Treasury Dealer”), the Company shall substitute
another Primary Treasury Dealer for that dealer.


 




    H-R-2


     


    

“Reference Treasury Dealer Quotations”
means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Company, of the
bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted
in writing to the Company by that Reference Treasury Dealer at 5:00 p.m. on the third Business Day preceding the Redemption Date.


 


Notice of any redemption will be mailed
at least 15 calendar days but no more than 60 calendar days before the Redemption Date to each Holder of the Securities of this
series to be redeemed. The second line of Section 1104 of the Base Indenture is amended to replace “30” with “15”
for purposes of the Securities of this series.


 


Unless the Company defaults in payment of
the Redemption Price, interest will cease to accrue on the Securities of this series or the portions of the Securities of this
series called for redemption on and after the Redemption Date.


 


If this Security is redeemed in part only,
a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.


 


2.            Special Mandatory Redemption.


 


If the Merger has not been completed by
December 31, 2016 (or such later date to which the End Date is extended by agreement between the Company and Humana pursuant to
the terms of the Merger Agreement) or if, prior to such date, the Merger Agreement is terminated, then the Company shall redeem
all of the Securities of this series on the Special Mandatory Redemption Date at a special mandatory redemption price equal to
101% of the aggregate principal amount of such Securities, plus accrued and unpaid interest from the date of initial issuance,
or the most recent date to which interest has been paid or provided for, whichever is later, to, but excluding, the Special Mandatory
Redemption Date.


 


The Company shall cause notice of a special
mandatory redemption to be transmitted to each Holder of the Securities of this series at its registered address, with a copy to
the Trustee, no later than 60 days after the occurrence of the event triggering the special mandatory redemption. If funds sufficient
to pay the special mandatory redemption price of the Securities of this series on the Special Mandatory Redemption Date (plus accrued
and unpaid interest, if any, to the Special Mandatory Redemption Date) are deposited with the Trustee on or before such Special
Mandatory Redemption Date, the Securities of this series will cease to bear interest on and after the Special Mandatory Redemption
Date.


 


“End Date” has the meaning
ascribed to such term in the Merger Agreement.


 


“Humana” means Humana
Inc., a Delaware corporation.


 


“Merger” means the acquisition
of Humana by the Company on the terms and subject to the conditions set forth in the Merger Agreement.


 




    H-R-3


     


    

“Merger Agreement” means
the Agreement and Plan of Merger, dated as of July 2, 2015, among the Company, Echo Merger Sub, Inc., Echo Merger Sub, LLC and
Humana, as amended from time to time.


 


“Special Mandatory Redemption Date”
means the 30th day (or if such day is not a Business Day, the first Business Day thereafter) following the transmission of a notice
of special mandatory redemption.


 


3.            Change of Control.


 


If a Change of Control Triggering Event
occurs with respect to the Securities of this series, unless the Company has exercised its right to redeem the Securities of this
series in full or the Company has redeemed, or is required to redeem, the Securities of this series in full pursuant to Section
2 of this Security, the Company will make an offer to each Holder of the Securities of this series (the “Change of Control
Offer”) to repurchase any and all (equal to $2,000 or an integral multiple of $1,000) of such Holder’s Securities
of this series at a repurchase price in cash equal to 101% of the aggregate principal amount of the Securities of this series to
be repurchased plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase (the “Change
of Control Payment”). Within 30 days following any Change of Control Triggering Event with respect to the Securities
of this series, the Company will mail a notice to Holders of the Securities of this series describing the transaction or transactions
that constitute the Change of Control Triggering Event and offering to repurchase the Securities of this series on the date specified
in the notice (the “Change of Control Payment Date”), which date will be no less than 30 days and no more than
60 days from the date such notice is mailed, pursuant to the procedures required hereby and described in such notice.


 


The Company will comply with the requirements
of Rule 14e-1 under the Securities Exchange Act of 1934, as amended from time to time, and any successor statute thereto (the “Exchange
Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable
in connection with the repurchase of the Securities of this series as a result of a Change of Control Triggering Event. To the
extent that the provisions of any securities laws or regulations conflict with the Change of Control repurchase provisions of the
Securities of this series, the Company will comply with the applicable securities laws and regulations and will not be deemed to
have breached its obligations under the Change of Control repurchase provisions of the Securities of this series by virtue of such
conflicts.


 


The Company will not be required to offer
to repurchase the Securities upon the occurrence of a Change of Control Triggering Event with respect to the Securities of this
series if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an
offer made by the Company and the third party repurchases on the applicable date all Securities of this series properly tendered
and not withdrawn under its offer; provided that for all purposes of the Securities of this series and the Indenture, a
failure by such third party to comply with the requirements of such offer and to complete such offer shall be treated as a failure
by the Company to comply


 




    H-R-4


     


    

with its obligations to offer to purchase
the Securities of this series unless the Company promptly makes an offer to repurchase the Securities of this series at 101% of
the outstanding principal amount thereof plus accrued and unpaid interest, if any, thereon, to, but excluding, the date of repurchase,
which shall be no later than 30 days after the third party’s scheduled Change of Control Payment Date.


 


On the Change of Control Payment Date, the
Company will, to the extent lawful:


 


		·	accept or cause a third party to accept for payment all Securities of this series or portions of Securities of this series
properly tendered pursuant to the Change of Control Offer;



 


		·	deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect
of each Security of this series or portion of a Security of this series properly tendered; and



 


		·	deliver or cause to be delivered to the Trustee the Securities of this series properly accepted, together with an officer’s
certificate stating the aggregate principal amount of Securities of this series or portions of Securities of this series being
purchased.



 


“Below Investment Grade Rating
Event” means the Securities of this series are rated below an Investment Grade Rating by each of the Rating Agencies
on any date from the earlier of (1) the occurrence of a Change of Control and (2) public notice of the Company’s intention
to effect a Change of Control, in each case until the end of the 60-day period following the earlier of (1) the occurrence of a
Change of Control and (2) public notice of the Company’s intention to effect a Change of Control; provided, however,
that if (i) during such 60-day period one or more Rating Agencies has publicly announced that it is considering the possible downgrade
of the Securities of this series, and (ii) a downgrade by each of the Rating Agencies that has made such an announcement would
result in a Below Investment Grade Rating Event for this series of Securities, then such 60-day period shall be extended for such
time as the rating of the Securities of this series by any such Rating Agency remains under publicly announced consideration for
possible downgrade to a rating below an Investment Grade Rating and a downgrade by such Rating Agency to a rating below an Investment
Grade Rating could cause a Below Investment Grade Rating Event for this series of Securities. Notwithstanding the foregoing, a
rating event otherwise arising by virtue of a particular reduction in rating will not be deemed to have occurred in respect of
a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for this series of Securities
for purposes of the definition of Change of Control Triggering Event) if the Rating Agencies making the reduction in rating to
which this definition would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at the Company’s
or the Trustee’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of
or arising as a result of, or in respect of, the applicable Change of Control (whether or not the applicable Change of Control
has occurred at the time of the rating event).


 




    H-R-5


     


    

“Change of Control” means
the occurrence of any of the following: (1) direct or indirect sale, transfer, conveyance or other disposition (other than by way
of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets
of the Company and its subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act) other than to the Company or one of its subsidiaries; or (2) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any “person” (as that term is used in Section
13(d)(3) of the Exchange Act) other than the Company or one of its subsidiaries becomes the beneficial owner, directly or indirectly,
of more than 50% of the then outstanding number of shares of the Company’s voting stock; provided, however, that a
transaction will not be deemed to involve a Change of Control if (A) the Company becomes a wholly owned subsidiary of a holding
company and (B)(x) the holders of the voting stock of such holding company immediately following that transaction are substantially
the same as the holders of the Company’s voting stock immediately prior to that transaction or (y) immediately following
that transaction no “person” (as that term is used in Section 13(d)(3) of the Exchange Act) is the beneficial owner,
directly or indirectly, of more than 50% of the voting stock of such holding company. For purposes of this definition, “voting
stock” means capital stock of any class or kind the holders of which are ordinarily, in the absence of contingencies,
entitled to vote for the election of directors (or persons performing similar functions) of the Company (even if the right to vote
has been suspended by the happening of such a contingency).


 


“Change of Control Triggering Event”
means the occurrence of both a Change of Control and a Below Investment Grade Rating Event.


 


“Fitch” means Fitch Ratings,
Inc.


 


“Investment Grade Rating”
means a rating by Moody’s equal to or higher than Baa3 (or the equivalent under any successor rating category of Moody’s),
a rating by S&P equal to or higher than BBB- (or the equivalent under any successor rating category of S&P), a rating by
Fitch equal to or higher than BBB- (or the equivalent under any successor rating category of Fitch), and the equivalent investment
grade credit rating from any replacement rating agency or rating agencies selected by the Company under circumstances permitting
the Company to select a replacement rating agency and in the manner for selecting a replacement rating agency, in each case as
set forth in the definition of “Rating Agencies.”


 


“Moody’s” means
Moody’s Investors Service, Inc.


 


“Rating Agencies” means
(1) Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the Securities of
this series or fails to make a rating of the Securities of this series publicly available for reasons outside of the Company’s
control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange
Act that the Company selects as a replacement agency for any of Moody’s, S&P or Fitch, or all of them, as the case may
be, with respect to the Securities of this series.


 




    H-R-6


     


    

“S&P” means Standard
& Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.


 


4.            Certain Covenants.


 


The Indenture contains certain covenants
that, among other things, limit the ability of the Company to consolidate, merge or sell all or substantially all of its assets.
These covenants are subject to a number of important qualifications and exceptions. Section 1005 of the Base Indenture, including,
without limitation, the limitation on liens on the Common Stock of Principal Subsidiaries set forth therein, does not apply to
the Securities of this series.


 


5.            Events of Default.


 


If an Event of Default with respect to Securities
of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture. The Event of Default set forth in Section 501(5) of the Base Indenture,
including, without limitation, the cross-acceleration provisions thereof, does not apply to the Securities of this series.


 


6.            Amendment, Modification and Waiver.


 


The Indenture permits, with certain exceptions
as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of
the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with
the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected.
The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of
each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent
or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security
and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation
of such consent or waiver is made upon this Security.


 


7.            Other Matters.


 


No reference herein to the Indenture and
no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional,
to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency,
herein prescribed.


 


As provided in the Indenture and subject
to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register upon surrender
of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly


 




    H-R-7


     


    

endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or such
Holder’s attorney duly authorized in writing, and thereupon one or more new Securities of this series and of like tenor,
of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.


 


The Securities of this series are issuable
only in registered form without coupons in denominations of $2,000 and any multiple of $1,000 in excess thereof. As provided in
the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate
principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.


 


No service charge shall be made for any
such registration of transfer or exchange of Securities, but the Company or the Trustee may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection with any registration of transfer or exchange of
Securities, other than exchanges pursuant to Section 304, 906 or 1107 of the Base Indenture not involving any transfer.


 


Prior to due and proper presentment of this
Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person
in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security is overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the contrary.


 


The Indenture provides that the Company,
at the Company’s option, (a) will be discharged from any and all obligations in respect of the Securities (except for certain
obligations to register the transfer or exchange of Securities, replace stolen, lost or mutilated Securities, maintain paying agencies
and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, in each case
if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations which through the payment of interest
thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal
of and premium, if any, and interest on, the Securities on the dates such payments are due in accordance with the terms of such
Securities, and certain other conditions are satisfied.


 


No recourse shall be had for the payment
of the principal of and premium, if any, or interest on this Security, or for any claim based hereon, or otherwise in respect hereof,
or based on or in respect of the Indenture or any indenture supplemental thereto, against any incorporator, stockholder, officer,
employee, agent or director, as such, past, present or future, of the Company or of any successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise, all such liability
being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.


 


All terms used in this Security which are
defined in the Indenture shall have the respective meanings assigned to them in the Indenture.


 








    H-R-8