Exhibit 10.1

EXECUTION VERSION

VOTING AGREEMENT

VOTING AGREEMENT (this “Agreement”), dated as of July 2, 2015, among Centene
Corporation, a Delaware corporation (“Parent”) and Jay M. Gellert
(“Stockholder”).

WHEREAS, in order to induce Parent, Chopin Merger Sub I, Inc., a Delaware
corporation and a direct wholly owned subsidiary of Parent, and Chopin Merger
Sub II, Inc., a Delaware corporation and a direct wholly owned subsidiary of
Parent, to enter into the Agreement and Plan of Merger, dated as of the date
hereof (as amended from time to time, the “Merger Agreement”), with Health Net,
Inc., a Delaware corporation (the “Company”), Parent has requested Stockholder,
and Stockholder has agreed, to enter into this Agreement with respect to all
shares of Company Common Stock (“Shares”) now or hereafter “beneficially owned”
by Stockholder.

NOW, THEREFORE, the parties hereto agree as follows:

ARTICLE 1

VOTING AGREEMENT; GRANT OF PROXY

Section 1.01 Voting Agreement. Stockholder shall (a) appear at each meeting of
the stockholders of the Company or otherwise cause all of the Shares
beneficially owned at such time by Stockholder to be counted as present thereat
for purposes of calculating a quorum, and respond to each request by Parent for
written consent, if any and (b) vote or cause to be voted (or deliver or cause
to be delivered a written consent with respect to) all Shares beneficially owned
at such time by Stockholder: (i) for the adoption of the Merger Agreement, the
Merger and other transactions contemplated by the Merger Agreement, and all
agreements in furtherance of the Merger and any actions in furtherance thereof
at any meeting of the stockholders of the Company, and at any adjournment or
postponement thereof, at which such Merger Agreement and other related
agreements (or any amended version thereof), or such other actions, are
submitted for the consideration and vote of the stockholders of the Company (or
in response to a request by the Company for written consent with respect
thereto) and (ii) against (A) any Takeover Proposal and (B) any other corporate
action the consummation of which would frustrate the purposes, or prevent or
materially delay the consummation, of the transactions contemplated by the
Merger Agreement; provided that nothing contained in this Section 1.01 shall
restrict Stockholder from taking any action in his capacity as a director,
officer or employee of the Company which is permitted to be taken pursuant to
the Merger Agreement.

Section 1.02 Irrevocable Proxy. Stockholder hereby revokes any and all previous
proxies granted by Stockholder with respect to Shares beneficially owned by him
as of the date of this Agreement. By entering into this Agreement, Stockholder
hereby irrevocably grants a proxy appointing, until the termination of this
Agreement in accordance with Section 5.03, Parent as Stockholder’s
attorney-in-fact and proxy, with full power of substitution and resubstitution,
for and in Stockholder’s name, to vote, or grant a written consent with respect
to, any Shares beneficially owned by Stockholders in the manner contemplated by
Section 1.01 if

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and only if Stockholder (i) fails to vote or (ii) attempts to vote such Shares
in a manner inconsistent with Section 1.01. The proxy granted by Stockholder
pursuant to this Section 1.02 is irrevocable and is granted in consideration of
Parent entering into this Agreement and the Merger Agreement and incurring
certain related fees and expenses. Stockholder hereby affirms that such
irrevocable proxy is coupled with an interest by reason of the Merger Agreement.
Notwithstanding the foregoing, the proxy granted by Stockholder pursuant to this
Section 1.02 shall be revoked and terminated upon termination of this Agreement
in accordance with its terms.

ARTICLE 2

REPRESENTATIONS AND WARRANTIES OF STOCKHOLDER

Stockholder represents and warrants to Parent that:

Section 2.01 Authorization. The execution, delivery and performance by
Stockholder of this Agreement and the consummation by Stockholder of the
transactions contemplated hereby are within the capacity of and have been duly
authorized by Stockholder. This Agreement constitutes a valid and binding
agreement of Stockholder and, assuming this Agreement constitutes a valid and
binding agreement of Parent, is enforceable against Stockholder, except as such
enforceability may be limited by (a) applicable bankruptcy, insolvency,
moratorium, reorganization or similar laws in effect that affect the enforcement
of creditors rights generally or (b) general principles of equity, whether
considered in a proceeding at law or in equity. If any of the Shares
beneficially owned by Stockholder constitute community property under applicable
Law, this Agreement has been duly authorized, executed and delivered by, and
constitutes the valid and binding agreement of, Stockholder’s spouse.

Section 2.02 Non-Contravention. The execution, delivery and performance by
Stockholder of this Agreement and the consummation of the transactions
contemplated hereby do not and will not (i) violate any applicable Law or
(ii) require any consent or other action by any Person under, constitute a
default under, or give rise to any right of termination, cancellation or
acceleration or to a loss of any benefit to which Stockholder is entitled under
any provision of any agreement or other instrument binding on Stockholder.

Section 2.03 No Other Voting Agreements. None of the Shares beneficially owned
by Stockholders are subject to any voting trust or other agreement or
arrangement with respect to the voting of such Shares (except as established
hereby) or that would otherwise have the effect of preventing or disabling
Stockholder from performing in any material respect any of its obligations under
this Agreement.

Section 2.04 Ownership. As of the date hereof, Stockholder is the beneficial
owner of less than 5.0% of the issued and outstanding Company Common Stock.
Stockholder is the sole beneficial owner and has and will have at all times
through the Closing Date sole beneficial ownership, sole voting power (including
the right to control such vote as contemplated herein), sole power of
disposition, sole power to issue instructions with respect to the matters set
forth in Article I hereof, and sole power to agree to all of the matters set
forth in this Agreement, and has not (i) granted any proxy inconsistent with
this Agreement that is still effective, (ii) entered into any voting or similar
agreement, or (iii) entered into any contract, option or other arrangement or

 

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understanding with respect to the direct or indirect Transfer (as defined
below), in each case with respect to any of the Shares beneficially owned by
Stockholder.

ARTICLE 3

REPRESENTATIONS AND WARRANTIES OF PARENT

Parent represents and warrants to Stockholder that:

Section 3.01 Authorization. The execution, delivery and performance by Parent of
this Agreement and the consummation by Parent of the transactions contemplated
hereby are within the capacity of and have been duly authorized by Parent. This
Agreement constitutes a valid and binding Agreement of Parent and, assuming this
Agreement constitutes a valid and binding agreement of Stockholder, is
enforceable against Parent, except as such enforceability may be limited by
(a) applicable bankruptcy, insolvency, moratorium, reorganization or similar
laws in effect that affect the enforcement of creditors rights generally or
(b) general principles of equity, whether considered in a proceeding at law or
in equity.

Section 3.02 Non-Contravention. The execution, delivery and performance by
Parent of this Agreement and the consummation of the transactions contemplated
hereby do not and will not (i) violate any applicable Law or (ii) require any
consent or other action by any Person under, constitute a default under, or give
rise to any right of termination, cancellation or acceleration or to a loss of
any benefit to which Parent is entitled under any provision of any agreement or
other instrument binding on Parent.

ARTICLE 4

COVENANTS OF STOCKHOLDER

Stockholder hereby covenants and agrees that:

Section 4.01 No Proxies for or Encumbrances on Shares. Stockholder shall not,
without the prior written consent of Parent, directly or indirectly, (i) grant
any proxies or enter into any voting trust or other agreement or arrangement
with respect to the voting of any Shares or (ii) sell, assign, transfer,
encumber or otherwise dispose of (“Transfer”), or enter into any contract,
option or other arrangement or understanding with respect to the direct or
indirect Transfer of, any Shares during the term of this Agreement or
(iii) create or permit to exist any Lien that could prevent Stockholder from
voting the Shares beneficially owned by him in accordance with this Agreement or
from complying in all material respects with the other obligations under this
Agreement. Any attempted Transfer of Shares in violation of this Section 4.01
shall be null and void.

Section 4.02 Additional Shares. Stockholder agrees to promptly notify Parent of
any additional Shares he acquires beneficial ownership of after the date hereof.
Any such Shares shall automatically become subject to the terms of this
Agreement. In the event Stockholder acquires in excess of 5.0% of the issued and
outstanding Company Common Stock, Stockholder shall promptly notify Parent and
cooperate in connection with any required filings with the United States
Securities and Exchange Commission.

 

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Section 4.03 No Solicitation. Stockholder hereby agrees that during the term of
this Agreement, Stockholder shall not take any action that Parent is otherwise
then prohibited from taking under Section 5.4 of the Merger Agreement.

Section 4.04 Disclosure. Stockholder hereby consents to and authorizes the
publication and disclosure by the Company and Parent in any press release or in
the Joint Proxy Statement or other disclosure document required in connection
with the Merger Agreement or the transactions contemplated thereby, of
Stockholder’s identity, the nature of Stockholder’s commitments, arrangements
and understandings pursuant to this Agreement and such other information
required in connection with such publication or disclosure. As promptly as
practicable, Stockholder shall notify the Company of any required corrections
with respect to such information previously supplied by Stockholder to the
Company or Parent hereunder, if and to the extent Stockholder becomes aware that
any such information shall have become false or misleading in any material
respect.

Section 4.05 Appraisal Rights. Stockholder agrees not to exercise any rights
(including under Section 262 of the General Corporation Law of the State of
Delaware) to demand appraisal of any Shares which may arise with respect to the
Merger.

ARTICLE 5

MISCELLANEOUS

Section 5.01 Definitional and Interpretative Provisions.

(a) Capitalized terms used but not defined herein shall have the respective
meanings set forth in the Merger Agreement.

(b) The words “hereof”, “herein” and “hereunder” and words of like import used
in this Agreement shall refer to this Agreement as a whole and not to any
particular provision of this Agreement. The captions herein are included for
convenience of reference only and shall be ignored in the construction or
interpretation hereof. Any singular term in this Agreement shall be deemed to
include the plural, and any plural term the singular. Whenever the words
“include”, “includes” or “including” are used in this Agreement, they shall be
deemed to be followed by the words “without limitation”, whether or not they are
in fact followed by those words or words of like import. “Writing”, “written”
and comparable terms refer to printing, typing and other means of reproducing
words (including electronic media) in a visible form. References to any
agreement or contract are to that agreement or contract as amended, modified or
supplemented from time to time in accordance with the terms hereof and thereof.
References to any Person include the successors and permitted assigns of that
Person. References from or through any date mean, unless otherwise specified,
from and including or through and including, respectively.

(c) For purposes of this Agreement, the term “beneficially owned” (and
correlative terms) has the meaning ascribed to it in Rule 13d-3 adopted by the
Securities and Exchange Commission under the Exchange Act.

 

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Section 5.02 Further Assurances. Parent and Stockholder will each execute and
deliver, or cause to be executed and delivered, all further documents and
instruments and use reasonable best efforts to take, or cause to be taken, all
actions and to do, or cause to be done, all things necessary, proper or
advisable under applicable Law, to consummate and make effective the
transactions contemplated by this Agreement.

Section 5.03 Amendments; Termination. Any provision of this Agreement may be
amended or waived if, but only if, such amendment or waiver is in writing and is
signed, in the case of an amendment, by each party to this Agreement, or in the
case of a waiver, by the party against whom the waiver is to be effective. This
Agreement shall terminate upon the earliest to occur of (x) the termination of
the Merger Agreement, (y) a Company Adverse Recommendation and (z) the receipt
of the Company Stockholder Approval (as defined in the Merger Agreement);
provided, the termination of this Agreement shall not relieve any party of
liability for any intentional and material breach prior to such termination.
Upon any termination of this Agreement, this Agreement shall thereupon become
void and of no further force and effect, and there shall be no liability in
respect of this Agreement or of any transactions contemplated hereby on the part
of any party hereto.

Section 5.04 Expenses. All costs and expenses incurred in connection with this
Agreement shall be paid by the party incurring such cost or expense.

Section 5.05 Successors and Assigns. The provisions of this Agreement shall be
binding upon and inure to the benefit of the parties hereto and their respective
successors and assigns; provided that no party may assign, delegate or otherwise
transfer any of its rights or obligations under this Agreement without the
consent of the other party hereto, except that Parent may transfer or assign its
rights and obligations to any Affiliate of Parent.

Section 5.06 Governing Law; Submission to Jurisdiction. This Agreement shall be
construed in accordance with and governed by the laws of the State of Delaware,
without regard to the conflicts of laws rules thereof. Each of the parties
hereto (a) irrevocably submits itself to the personal jurisdiction of the
Delaware Court of Chancery and any state appellate court therefrom within the
State of Delaware (or, if the Delaware Court of Chancery declines to accept
jurisdiction over a particular matter, any state or federal court within the
State of Delaware) and any state appellate court therefrom within the State of
Delaware in the event any dispute arises out of this Agreement, (b) agrees that
it will not attempt to deny or defeat such personal jurisdiction by motion or
other request for leave from any such court, (c) agrees that it will not bring
any action relating to this Agreement in any court other than such court, other
than actions in any court of competent jurisdiction to enforce any judgment,
decree or award rendered by any such court, and (d) waives any right to trial by
jury with respect to any suit, action or proceeding directly or indirectly
related to or arising out of this Agreement. Each of the parties hereto further
agrees that notice sent via a nationally recognized overnight courier service to
the address set forth below such party’s signature hereto shall constitute
sufficient service of process and waives any argument that such service is
insufficient. Each of the parties hereto hereby irrevocably and unconditionally
waives, and agrees not to assert, by way of motion or as a defense, counterclaim
or otherwise, in any action related to or arising out of this Agreement, that
(x) the action in such court is brought in an inconvenient forum, (y) the venue
of such action is

 

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improper or (z) this Agreement or the subject matter hereof may not be enforced
in or by such court.

Section 5.07 Counterparts; Effectiveness. This Agreement may be signed in any
number of counterparts, each of which shall be an original, with the same effect
as if the signatures thereto and hereto were upon the same instrument. This
Agreement shall become effective when each party hereto shall have received
counterparts hereof signed by all of the other parties hereto. Until and unless
each party has received a counterpart hereof signed by the other party hereto,
this Agreement shall have no effect and no party shall have any right or
obligation hereunder (whether by virtue of any other oral or written agreement
or other communication).

Section 5.08 Severability. If any term, provision or covenant of this Agreement
is held by a court of competent jurisdiction or other authority to be invalid,
void or unenforceable, the remainder of the terms, provisions and covenants of
this Agreement shall remain in full force and effect and shall in no way be
affected, impaired or invalidated.

Section 5.09 Specific Performance. The parties hereto agree that irreparable
damage would occur in the event any provision of this Agreement is not performed
in accordance with the terms hereof and that the parties shall be entitled to
specific performance of the terms hereof in addition to any other remedy to
which they are entitled at law or in equity (without a requirement for posting
of a bond in connection therewith). Each party agrees that it will not oppose
the granting of an injunction, specific performance and other equitable relief
on the basis that (a) the other party has an adequate remedy at law or (b) an
award of specific performance is not an appropriate remedy for any reason at law
or equity.

Section 5.10 Entire Agreement; No Third-Party Beneficiaries. This Agreement
constitutes the sole and entire agreement of the Stockholder and Parent with
respect to the subject matter contained herein, and supersedes all prior and
contemporaneous agreements with respect to such subject matter. This Agreement
is for the sole benefit of and may be enforced solely by Parent, and nothing in
this Agreement, express or implied, is intended to or shall confer upon any
person (other than Parent) any legal or equitable right, benefit or remedy of
any nature whatsoever.

Section 5.11 Ownership Interest. Nothing contained in this Agreement shall be
deemed to vest in Parent any direct or indirect ownership or incidence of
ownership of or with respect to any Shares beneficially owned by Stockholder.
All rights, ownership and economic benefits of and relating to such Shares shall
remain vested in and belong to Stockholder, and Parent shall not have any
authority to direct the Stockholder in the voting or disposition of such Shares
except as otherwise provided herein.

Section 5.12 Capacity. Stockholder is entering into this Agreement solely in his
capacity as the record holder or beneficial owner of the Shares and nothing
herein shall limit or affect any actions taken by Stockholder in his capacity as
director or officer of the Company.

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IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly
executed as of the day and year first above written.

 

Centene Corporation By:

/s/ Jeffrey A. Schwaneke

Name: Jeffrey A. Schwaneke Title: Senior Vice President, Corporate Controller
and Chief Accounting Officer

/s/ Jay M. Gellert

Jay M. Gellert