EXECUTIVE EMPLOYMENT AGREEMENT

        This Executive Employment Agreement (the “Agreement”) dated as of
October 29, 2004 (the “Effective Date”), by and between Express Scripts, Inc., a
Delaware corporation (the “Company”), and Thomas M. Boudreau (“Executive”).

        WHEREAS, Executive is now and has been employed by the Company as Senior
Vice President and General Counsel pursuant to the terms of that certain
Executive Employment Agreement dated as of March 15, 2001, as amended (the
“Prior Agreement”); and

        WHEREAS, the Company and Executive mutually desire to terminate the
Employment Period under the Prior Agreement, as defined therein, and to replace
the Prior Agreement with this Agreement to provide for the continued employment
of Executive on the terms and conditions set forth herein, all effective as of
the Effective Date;

        NOW, THEREFORE, in consideration of the premises and the mutual
covenants herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

ARTICLE I
DEFINITIONS

        As used herein, the following terms shall have the following meanings:

        1.1     “Accrued Rights ” has the meaning set forth in Section 4.1.

         1.2     “Annual Base Salary” means the base salary set forth in Section
3.1 hereof.

        1.3     “Annual Bonus” means Executive’s annual bonus granted pursuant
to the Annual Bonus Plan, as described in Section 3.2 hereof.

        1.4     “Annual Bonus Plan” means the annual bonus program established
for senior executives by the Board of Directors of the Company (the “Board”) or
by the Committee, as adopted or amended from time to time.

        1.5     “Bonus Potential” means the maximum bonus amount Executive could
receive pursuant to Section 3.2 hereof for achieving 100% of “base” or
“targeted” performance goals established by the Board or Committee under the
Annual Bonus Plan with respect to the applicable fiscal year; provided, however,
in no event shall Executive’s Bonus Potential for the year in which the Bonus
Potential is being determined (a) be less than $224,000, or, if greater, 64% of
Executive’s Annual Base Salary as in effect on January 1 of such year or (b)
take into account, or include in any way, any increase in Executive’s bonus
amount due to the Company exceeding its “base” or “target” goals for such year
(e.g., if Executive’s “base” or “target” Bonus Potential is stated at $50,000,
but Executive is eligible to receive more than $50,000 if certain targets are
exceeded then Executive’s Bonus Potential for purposes of this definition is
$50,000).

        1.6     "Cause" means:

    (a)        any act or acts by Executive, whether or not in connection with
his or her employment by the Company, constituting, or Executive’s conviction or
plea of guilty or nolo contendere (no contest) to, (i) a felony under applicable
law or (ii) a misdemeanor involving moral turpitude;

    (b)        any act or acts of gross dishonesty or gross misconduct in the
performance of Executive’s duties hereunder;

    (c)        any willful malfeasance or willful misconduct by Executive in
connection with Executive’s duties hereunder or any act or omission which is
materially injurious to the financial condition or business reputation of the
Company or its affiliates; or

    (d)        any breach by Executive of the provisions of Sections 5.1 through
5.3 of this Agreement, or of the terms and provisions of the Nondisclosure and
Noncompetition Agreement (as defined in Section 1.26 hereof).

                     Notwithstanding the foregoing, the event(s) described in
clause (c) of this Section 1.6 shall not be deemed to constitute “Cause” if such
event is (i) primarily the result of bad judgment or negligence on the part of
Executive not rising to the level of gross negligence; or (ii) primarily because
of an act or omission believed by Executive in good faith to have been in, or
not opposed to, the interests of the Company and its affiliates.

        1.7     “Change in Control” means a Change in Control as that term is
defined in the Incentive Plan (as defined in Section 1.24 hereof).

        1.8     “Change in Control Date” means the Change in Control Date as
that term is defined in the Incentive Plan.

        1.9     “Change in Control Period” means the ninety (90) day period
commencing on the Change in Control Date.

        1.10     “Change in Control Price” means the value, expressed in
dollars, as of the date of receipt of the per share consideration received by
the Company’s stockholders whose stock is acquired in a transaction constituting
a Change in Control.

        1.11     “Code” means the Internal Revenue Code of 1986, as amended.

        1.12     “Committee” means the Compensation and Development Committee of
the Board.

        1.13     “Covered Payments” means the amounts described in Section
6.12(a) hereof.

        1.14     “Deferred Bonus” means the bonus described in Section 3.6
hereof; provided, however, for purposes of determining the total amount of the
Deferred Bonus payable upon distribution from the Deferred Compensation Plan,
the amount in Section 3.6 hereof will be adjusted to take into account any
interest, earnings or other gains accrued thereon and any losses resulting from
investment of the Deferred Bonus in the investment selections under the Deferred
Compensation Plan.

        1.15     “Deferred Compensation Plan” means the Express Scripts, Inc.
Executive Deferred Compensation Plan, as amended from time to time, or any
successor plan.

        1.16     “Disability” has the meaning ascribed to such term in the
Incentive Plan.

        1.17     “EBITDA” means earnings before interest, taxes, depreciation
and amortization.

        1.18     “Effective Date” means the date specified in the recitals to
this Agreement.

        1.19     “Employment Period” means the Initial Employment Period (as
defined in Section 1.25 hereof) plus any additional Renewal Periods (as defined
in Section 1.30 hereof).

        1.20     “EPS” means the earnings per share of the Company.

        1.21     “Excise Tax” means the excise tax imposed by Section 4999 of
the Code or any similar state or local tax that may be imposed.

        1.22     “General Release” means the General Release and Acknowledgment
attached hereto as Exhibit A.

        1.23     “Good Reason” means the occurrence of any one or more of the
following:

      (a)        Any material breach by the Company of any of the provisions of
this Agreement or any material failure by the Company to carry out any of its
obligations hereunder;

      (b)        The Company’s requiring Executive to be based at any office or
location more than 50 miles from 13900 Riverport Drive, Maryland Heights,
Missouri (the “Current Headquarters”), except for travel reasonably required in
the performance of Executive’s responsibilities to the extent substantially
consistent with Executive’s business travel obligations;

      (c)        Any substantial and sustained diminution in Executive’s
authority or responsibilities from those described in Section 2.3 hereof;
provided, however, notwithstanding the foregoing, (i) in the event a Change in
Control shall occur which results in the Company becoming a subsidiary of
another pharmacy benefit management company (“PBM”), or which is in the form of
a merger in which the surviving corporation or entity is a PBM (x) so long as
Executive is offered a position as an officer of the parent PBM (or surviving
corporation or entity) with duties and responsibilities which are not
inconsistent in any material adverse respect with his or her duties and
responsibilities immediately prior to such Change in Control, and such position
is based at an office or location not more than 50 miles from the Current
Headquarters, such change in position shall not constitute Good Reason, but (y)
if Executive is not offered a position as an officer of the parent PBM or
surviving corporation or entity as described in (x), a substantial and sustained
diminution in Executive’s authority or responsibility shall be deemed to have
occurred; or (ii) in the event a Change in Control shall occur which results in
the Company becoming a subsidiary of a non-PBM or is in the form of a merger in
which the surviving corporation or entity is not a PBM, failure to receive an
offer to serve as an officer of the non-PBM parent or surviving corporation or
entity shall not constitute Good Reason provided Executive’s duties subsequent
to the Change in Control are not inconsistent in any material adverse respect
with his or her duties immediately prior to the Change in Control, and such
position is based at an office or location not more than 50 miles from the
Current Headquarters;

      (d)        The failure by the Company to continue to provide Executive
with substantially similar perquisites or benefits Executive enjoyed in the
aggregate under the Company’s benefit programs (other than long-term incentive
compensation programs), such as any of the Company’s pension, savings, vacation,
life insurance, medical, health and accident, or disability plans in which he or
she was participating at the time of any such discontinuation (or,
alternatively, if such plans are amended, modified or discontinued,
substantially similar equivalent benefits thereto in the aggregate), or the
taking of any action by the Company which would directly or indirectly cause
such benefits to be no longer substantially equivalent in the aggregate to the
benefits in effect immediately prior to taking such action; provided, that any
amendment, modification or discontinuation of any plans or benefits referred to
in this subsection (d) hereof that generally affect substantially all other
domestic salaried employees of the Company who were eligible to participate, and
participated, in the affected Company benefit program(s) shall not be deemed to
constitute Good Reason; and

      (e)        The failure by the Committee to approve the grants of
restricted stock or stock options specifically referenced in Sections 3.4 and
3.5 below within ninety (90) days of the Effective Date;

provided that the events described in Section 1.23 (a), (b), (c), (d) or (e)
above shall only constitute Good Reason if the Company fails to cure such event
within 30 days after receipt from Executive of written notice of the event which
constitutes Good Reason; and provided further that, “Good Reason” shall cease to
exist for an event on the 120th day following the later of its occurrence or
Executive’s knowledge thereof, unless Executive has given the Company written
notice thereof prior to such date.

        1.24     “Incentive Plan” means the Express Scripts, Inc. 2000 Long-Term
Incentive Plan, as amended from time to time.

        1.25     “Initial Employment Period” has the meaning set forth in
Section 2.2 hereof.

        1.26     “Nondisclosure and Noncompetition Agreement” means the Form of
Nondisclosure and Noncompetition Agreement entered into by and between Executive
and the Company dated as of February 29, 1996.

        1.27     “Option” means the option to purchase the number of shares of
the Company’s common stock as set forth in Section 3.4 hereof.

        1.28     “Payment Cap” means the maximum amount described in Section
6.12(b) hereof.

        1.29     “Pro Rata Deferred Bonus” means a pro rata payment of the
Deferred Bonus equal to the product of (i) the Deferred Bonus multiplied by (ii)
a fraction, the numerator of which is the number of days which have elapsed in
the Initial Employment Period through the Termination Date and the denominator
of which is the total number of days in the Initial Employment Period.
Notwithstanding the foregoing, in the event the termination of Executive’s
employment results from Executive’s death, the Pro Rata Deferred Bonus shall be
100% of the Deferred Bonus. As set forth in Section 1.14 hereof, the calculation
of the Pro Rata Deferred Bonus shall not include any installments of the
Deferred Bonus which either have not already been credited by the Company, or
with respect to which the Company’s obligation to credit such installment(s) has
not vested.

        1.30     “Renewal Period” has the meaning set forth in Section 2.2
hereof.

        1.31     “Restricted Stock” means shares of the Company’s common stock,
$0.01 par value per share, which are issued pursuant to the Incentive Plan and
subject to one or more restrictions prescribed by the Board or the by Committee,
in the sole discretion of either, as applicable.

        1.32     “Retirement” means the voluntary termination of employment by
Executive on or after attaining age 59 1/2 which does not occur during a Change
in Control Period.

        1.33     “Retirement Account” means Executive’s Retirement Account (as
defined in the Deferred Compensation Plan).

        1.34     “Severance Benefit” means a severance payment in an amount
equal to:

      (a)        eighteen (18) months of Executive’s Annual Base Salary as in
effect immediately prior to the Termination Date, plus

      (b)        an amount equal to the product of (i) Executive’s Bonus
Potential for the year in which the Termination Date occurs (the “Termination
Year”), multiplied by (ii) the average percentage of the Bonus Potential earned
by the Executive for the three (3) full years immediately preceding the
Termination Year, (or such shorter period if Executive was employed by the
Company for less than three (3) full years and received, or was eligible to
receive, a bonus during such period), which product shall be prorated for the
portion of the Termination Year in which Executive was employed by the Company.
Notwithstanding anything to the contrary herein, neither the three-year average
percentage of Bonus Potential described in (ii) above, nor the percentage for
any single year used to compute such three-year average, may exceed 100%.

        1.35     “Tax Reimbursement Payment” means the payment described in
Section 6.12(c) hereof.

        1.36     “Termination Date” means the effective date of termination of
Executive’s employment as determined in accordance with Section 4.7 hereof.

        1.37     “Welfare Benefit” has the meaning set forth in Section 4.2.

ARTICLE II
TERM/POSITION

        2.1     Employment; Effectiveness of Agreement. Effective as of the
Effective Date, the Company hereby employs Executive, and Executive hereby
accepts such employment, according to the terms and conditions set forth in this
Agreement.

        2.2     Term. Subject to the provisions of Sections 4.1 through 4.7 of
this Agreement, the term of Executive’s employment hereunder shall commence on
the Effective Date and continue through March 31, 2006 (the “Initial Employment
Period”). On April 1st of each year, commencing with April 1, 2006 and on each
subsequent April 1st thereafter (each, an “Anniversary Date”), this Agreement
shall be extended automatically at such time for an additional twelve (12) month
period (each, a “Renewal Period”) unless either party hereto delivers written
notice in accordance with Section 6.2 hereof to the other party hereto at least
30 days prior to such Anniversary Date of his, her or its desire not to renew
this Agreement for an additional Renewal Period. The Initial Employment Period
and any Renewal Periods, if any, shall constitute the “Employment Period” for
purposes of this Agreement. If there are no Renewal Periods, then the Employment
Period shall have the same meaning as Initial Employment Period. Except as set
forth in Section 6.1 hereof, upon termination of Executive’s employment with the
Company in accordance with the terms hereof or upon termination of the Initial
Employment Period or the Employment Period without extension thereof, this
Agreement shall terminate and no longer be of any force or effect.

        2.3     Position and Duties. Executive shall hold the position of Senior
Vice President and General Counsel and shall report to, and at all times be
subject to the lawful direction of, the Chief Executive Officer or President of
the Company (as designated by the Chief Executive Officer of the Company).
Additionally, Executive shall serve as a member of the executive staff and
participate in the strategic decision-making of the Company from time to time.
During the Employment Period, Executive shall devote his or her best efforts and
his or her full business time and attention (except for permitted vacation
periods and reasonable periods of illness or other incapacity) to the business
affairs of the Company. Executive shall perform his or her duties and
responsibilities to the best of his or her abilities in a diligent, trustworthy,
businesslike and efficient manner. Nothing herein shall preclude Executive from,
(a) subject to the prior written consent of the Board, serving on any for-profit
corporate or governmental board of directors (b) serving on the board of, or
working for, any charitable, not-for-profit or community organization, (c)
pursuing his or her personal, financial and legal affairs, or (d) pursuing any
other activity; provided that Executive shall not engage in any other business,
profession, occupation or other activity, for compensation or otherwise, which
would violate the provisions of Section 5.1 or would, in each case, and in the
aggregate, otherwise conflict or interfere with the performance of Executive’s
duties and responsibilities hereunder, either directly or indirectly, without
the prior written consent of the Board

ARTICLE III
COMPENSATION AND BENEFITS

        3.1     Annual Base Salary. During the Employment Period, the Company
shall pay Executive a base salary (the “Annual Base Salary”) at the annual rate
of three hundred fifty thousand Dollars ($350,000), which shall be payable in
regular installments in accordance with the Company’s usual payroll practices
and shall be subject to deductions for customary withholdings, including,
without limitation, federal, state and local withholding taxes, social security
taxes and Medicare taxes. Executive shall be eligible for such merit-based
increases in Executive’s Annual Base Salary, if any, as may be determined from
time to time in the sole discretion of the Board; provided that any such
increase shall not serve to limit or reduce any other obligation to Executive
under this Agreement. The term “Annual Base Salary” as used in this Agreement
shall refer to the Annual Base Salary as in effect from time to time during the
Employment Period. Executive’s Annual Base Salary shall not be reduced after any
such increase without Executive’s express written consent.

        The parties agree that the amount of Annual Base Salary shall be deemed
effective as of January 1, 2004. In order to account for the retroactive
increase in salary, the Company shall, within thirty days of the Effective Date,
deliver a one-time payment to Executive in an amount equal to the difference
between the salary paid to Executive for the period from January 1, 2004 through
the Effective Date and the salary which would have been paid during such period
had the Annual Base Salary been in effect. Such payment shall be to deductions
for customary withholdings and the Company’s standard payroll policies and
procedures.

        3.2     Annual Incentive Compensation. Executive shall be eligible to
participate in the Company’s Annual Bonus Plan established for senior executives
by the Board or the Committee. The size of Executive’s bonus opportunity, which
shall be no less than the Bonus Potential, and the terms of Executive’s
participation in the Annual Bonus Plan, shall be determined based on the terms
and conditions of the Annual Bonus Plan, subject to adjustment as described
therein. Executive’s Annual Bonus shall be based upon performance of Executive,
Executive’s department, and/or the Company in relation to the financial and
non-financial objectives to be established by the Board or by the Committee, at
the sole discretion of either, as applicable, pursuant to the terms of the
Annual Bonus Plan. Executive’s Annual Bonus shall be subject to deductions for
customary withholdings, including, without limitation, federal, state and local
withholding taxes, social security taxes and Medicare taxes. Subject to the
achievement or failure to achieve the relevant financial and non-financial
objectives under the Annual Bonus Plan, Executive may receive, for any given
year, from 0% to 200% of Executive’s Bonus Potential (or such higher percentage
as may be achievable pursuant to the terms of the Annual Bonus Plan), as further
set forth in the Annual Bonus Plan.

        3.3     Participation in Benefit and Incentive Plans. During the
Employment Period, Executive shall be entitled to participate in the Company’s
employee benefit plans (other than bonus and incentive plans) as in effect from
time to time, on the same basis as those benefits are generally made available
to similarly situated senior executives of the Company. The payments provided in
Article III hereof are in addition to benefits which Executive is entitled to
receive pursuant to the terms of any pension plan or group hospitalization,
health, dental care, disability insurance, death benefit, travel and/or accident
insurance, or executive compensation plan or arrangement, including, without
limitation, the Incentive Plan and the Deferred Compensation Plan.

        3.4     Stock Options.

    (a)        Executive will receive a non-qualified option to purchase nine
thousand, six hundred and fifty-five (9,655) shares of the Company’s common
stock (the “Performance-Based Option”), subject to approval by the Committee and
to the terms and conditions of this Agreement, the applicable option agreement
or notice and the Incentive Plan, with a purchase price equal to the Fair Market
Value (as defined in the Incentive Plan) of the Company’s common stock on the
date of grant subject to adjustment pursuant to the terms of the Incentive Plan
(the “Exercise Price”). The Performance-Based Option shall vest on December 31,
2010 (subject to acceleration as set forth in Section 3.4(b) below), provided
Executive is still employed by the Company on such date and subject to such
other vesting terms as may be provided in the Incentive Plan and the applicable
option agreement or notice. The Performance-Based Option shall expire seven (7)
years from the date of grant, subject to earlier expiration following
Executive’s termination of employment as may be provided in the Incentive Plan
and the applicable option agreement or notice.

    (b)        Notwithstanding the foregoing, the vesting of the
Performance-Based Option may be accelerated if certain financial targets and
other conditions are met in accordance with vesting provisions adopted by the
Board or the Committee and set forth in the applicable option agreement or
notice, subject to the terms of the Incentive Plan and the applicable option
agreement or notice.

    (c)        Notwithstanding the standard provisions of the Incentive Plan,
(i) the Performance-Based Option shall not vest or otherwise become exercisable
solely as a result of either Executive’s Retirement hereunder or Executive’s
“Retirement” under the Incentive Plan (as such term is defined therein) and (ii)
Executive shall be entitled to exercise any portion of the Option which has
become vested and exercisable as of the Termination Date until the expiration of
the seven-year option term unless (A) Executive’s employment is terminated by
the Company for Cause, or (B) Executive’s employment is terminated by the
Executive other than for Good Reason and prior to April 1, 2007, in which event
(i.e. the occurrence either of the events in (A) or (B)) the standard provisions
of the Incentive Plan shall apply.

        3.5     Restricted Stock.

    (a)        Executive will receive Seven Thousand Two Hundred Twenty-Six
(7,226) shares of Restricted Stock, subject to approval by the Committee and to
the terms and conditions of this Agreement, the applicable restricted stock
agreement and the Incentive Plan. For the purposes hereof, Six Thousand Twenty
(6,020) shares of the above-described Restricted Stock shall be referred to as
the “Target Shares.”

    (b)        Notwithstanding the standard provisions in the Incentive Plan,
the Restricted Stock awarded pursuant to Section 3.5(a) hereof shall vest or be
forfeited in accordance with the following:

    (i)      If Executive remains in the employ of the Company until the seventh
anniversary of the date the Restricted Stock is granted by the Committee (the
“Restricted Stock Vesting Date”), Executive shall become fully vested in the
Restricted Stock subject to this Agreement. Unless either Section 3.5(b)(ii) or
3.5(b)(iii) shall apply, if Executive’s employment is terminated prior to the
Restricted Stock Vesting Date, all shares of Restricted Stock awarded pursuant
to Section 3.5(a) hereof shall be forfeited without payment of consideration by
the Company.

    (ii)      Notwithstanding the foregoing, the vesting of the Restricted Stock
may be accelerated if certain financial targets and other conditions are met in
accordance with in accordance with vesting provisions adopted by the Board or
the Committee and set forth in the applicable restricted stock agreement.

    (iii)      To the extent the Restricted Stock awarded pursuant to Section
3.5(a) hereof does not otherwise vest pursuant to Section 3.5(b)(ii), if, prior
to the Restricted Stock Vesting Date, either Executive terminates employment on
account of death, Disability or for Good Reason, or Executive is terminated by
the Company on account of Disability or other than for Cause, Executive shall
become vested in a portion of the unvested Restricted Stock awarded pursuant to
Section 3.5(a) hereof equal to the product of (x) the Target Shares, multiplied
by (y) a fraction, the numerator of which is the number of days which have
elapsed in the Initial Employment Period through the Termination Date and the
denominator of which is the total number of days in the Initial Employment
Period; provided, however, that, notwithstanding such formula, in the event such
termination is on account of Executive’s death, the product of (x) and (y) above
shall be deemed to be the full amount of the Target Shares. Shares of Restricted
Stock awarded pursuant to Section 3.5(a) hereof which have not otherwise vested
pursuant to either Section 3.5(b)(ii) hereof or the preceding sentence of this
Section 3.5(b)(iii) shall be forfeited without payment of consideration by the
Company.

    (c)        Notwithstanding the standard provisions of the Incentive Plan,
the Restricted Stock shall not vest or otherwise become exercisable solely as a
result of either Executive’s Retirement hereunder or Executive’s “Retirement”
under the Incentive Plan (as such term is defined therein).

        3.6     Deferred Bonus.

    (a)        In addition to any other bonus or deferred compensation benefit
described in Article III hereof, or to which Executive is otherwise entitled
pursuant to another plan or arrangement with the Company, the Company agrees to
credit four hundred thousand dollars ($400,000) (the “Deferred Bonus”) to
Executive’s Retirement Account as deferred compensation under the Deferred
Compensation Plan, subject to the terms and conditions hereof. The Deferred
Bonus shall be credited in two equal installments of two hundred thousand
dollars ($200,000) each as follows: (i) the first installment shall be credited
as soon as practicable following the Effective Date, and (ii), the second
installment shall be credited on January 1, 2005; provided, that in the event
Executive’s employment with the Company is terminated for any reason prior to
January 1, 2005, the Company shall have no obligation to credit the second
installment of the Deferred Bonus and Executive shall have no rights with
respect to such second installment.

    (b)        Notwithstanding anything to the contrary in the Deferred
Compensation Plan, in the event Executive’s employment with the Company is
terminated prior to expiration of the Initial Employment Period, Executive shall
forfeit all of the Deferred Bonus, without payment of consideration by the
Company, except as otherwise provided in Section 3.6(e) hereof. In the event a
distribution is otherwise made from Executive’s Retirement Account pursuant to
the rules set forth in the Deferred Compensation Plan prior to expiration of the
Initial Employment Period, no portion of the Retirement Account traceable to the
Deferred Bonus shall be eligible for distribution from the Retirement Account at
such time, except as otherwise provided in Section 3.6(e).

    (c)        Subject to Section 3.6(f) hereof, provided Executive remains in
the employ of the Company until expiration of the Initial Employment Period,
Executive shall be entitled to receive a distribution of the Deferred Bonus
after expiration of the Employment Period at the time and in the manner provided
under the Deferred Compensation Plan.

    (d)        If, prior to March 31, 2006, either Executive terminates
employment on account of Retirement, death, Disability or for Good Reason, or
Executive is terminated by the Company on account of Disability or other than
for Cause, Executive shall be entitled to receive a Pro Rata Deferred Bonus;
provided, however, Executive shall be entitled to receive the Pro Rata Deferred
Bonus only if he or she is not otherwise entitled to receive the entire Deferred
Bonus pursuant to Section 3.4(e) hereof as of the Termination Date.
Notwithstanding the foregoing, Executive agrees that payment of any Pro Rata
Deferred Bonus is contingent upon the terms of Section 4.2(c) hereof. Payment of
the Pro Rata Deferred Bonus is subject to deductions for customary withholdings,
including, without limitation, federal, state and local withholding taxes,
social security taxes and Medicare taxes.

    (e)        Subject to Section 3.6(f) hereof, Executive shall obtain a vested
right to receive the Deferred Bonus upon a Change in Control as follows:

    (i)        If the Change in Control occurs prior to expiration of the
Initial Employment Period and Executive remains in the employ of the Company
through the end of the Change in Control Period, Executive shall obtain a vested
right to receive one-half of the Deferred Bonus, with the remaining one-half
otherwise eligible for vesting pursuant to the terms set forth in Sections
3.6(b), 3.6(c) and 3.6(e) hereof.

    (ii)        If the Change in Control occurs prior to expiration of the
Initial Employment Period and Executive is terminated by the Company other than
for Cause or Disability, or Executive terminates for Good Reason, either during
the ninety (90) day period immediately preceding the Change in Control Date
(provided such Change in Control was public knowledge as of the Termination
Date) or at any time after the occurrence of such Change in Control but prior to
the expiration of the Initial Employment Period, Executive shall obtain a vested
right to receive the entire Deferred Bonus.

    (iii)        If the Initial Employment Period expires during the Change in
Control Period (i.e., March 31, 2006 falls within the Change in Control Period),
Executive shall obtain a vested right to receive the entire Deferred Bonus on
such expiration date regardless of whether Executive remains in the employ of
the Company after such date pursuant to the terms of this Agreement or
otherwise.

  Any portion of the Deferred Bonus to which Executive becomes entitled to
receive pursuant to this Section 3.6(e) shall be payable at the time and in the
manner provided under the Deferred Compensation Plan.

    (f)        As a condition to entitlement to the Deferred Bonus pursuant to
Section 3.6(c) or 3.6(e) hereof, Executive shall be required to honor, in
accordance with their terms, the provisions of Sections 5.1, 5.2 and 5.3 hereof
(and the terms and provisions of the General Release and the Nondisclosure and
Noncompetition Agreement). In the event Executive fails to honor any such
provision, payments of the Deferred Bonus, and any accrued interest, earnings or
other gains thereon, to which Executive may otherwise have been entitled
pursuant to Section 3.6(c) or 3.6(e) hereof shall immediately cease and
Executive shall immediately forfeit all right, title and interest in and to any
remaining Deferred Bonus and Executive shall promptly pay to the Company any and
all Deferred Bonus amounts which have already been paid, allocated or provided
by the Company to Executive.

        3.7     Signing Bonus. In exchange for his execution of this Agreement,
Executive shall be entitled to receive a signing bonus in the amount of one
hundred thousand dollars ($100,000) payable in two equal installments of fifty
thousand dollars ($50,000) each as follows: (i) the first installment shall be
paid as soon as practicable following the Effective Date, and (ii), the second
installment shall vest as of January 1, 2005 and shall be paid as part of the
Company’s first, regular payroll cycle following January 1, 2005; provided, that
in the event Executive’s employment with the Company is terminated for any
reason prior to January 1, 2005, the Company shall have no obligation to pay the
second installment of the signing bonus and Executive shall have no rights with
respect to such second installment. Each installment of Executive’s signing
bonus shall be subject to deductions for customary withholdings, including,
without limitation, federal, state and local withholding taxes, social security
taxes and Medicare taxes.

        3.8     Business Expenses. During the Employment Period, Executive shall
be reimbursed for all reasonable expenses incurred by him in performing his or
her duties hereunder provided that such expenses are incurred and accounted for
in accordance with the policies and procedures established by the Company.

        3.9     Perquisites. During the Employment Period, Executive shall be
entitled to receive such perquisites and fringe benefits which similarly
situated executives of the Company are entitled to receive and such other
perquisites which are suitable to the character of Executive’s position with the
Company and adequate for the performance of Executive’s duties hereunder.

ARTICLE IV
TERMINATION OF EMPLOYMENT

        4.1     Termination by the Company for Cause; Termination by Executive
Other Than for Good Reason or Retirement. If the Employment Period and
Executive’s employment under this Agreement is terminated by the Company for
Cause or by Executive other than for Good Reason or Retirement, prior to the
scheduled expiration of the Employment Period, Executive shall be entitled to
receive:

    (a)        The Annual Base Salary through the Termination Date;

    (b)        Any Annual Bonus earned for a previously completed fiscal year,
but unpaid as of the Termination Date;

    (c)        Reimbursement for any unreimbursed business expenses properly
incurred by Executive in accordance with Company policy prior to the Termination
Date; and

    (d)        Such employee benefits, if any, as to which Executive may be
entitled under the employee benefit plans of the Company, including rights with
respect to the Performance-Based Option and the Restricted Stock subject to the
terms and conditions of Sections 3.4 and 3.5 hereof and of the Incentive Plan
and the applicable option or agreement or notice, if relevant (the amounts
described in clauses (a) through (d) hereof being referred to as the “Accrued
Rights”).

Following such termination of Executive’s employment hereunder pursuant to this
Section 4.1, Executive shall have no further rights to any compensation or any
other benefits under this Agreement.

        4.2     Termination by the Company Other Than for Cause or Disability;
Termination by Executive for Good Reason.

    (a)        If the Employment Period and Executive’s employment under this
Agreement is terminated by the Company prior to the scheduled expiration of the
Employment Period other than for Cause or Disability, or Executive terminates
his or her employment prior to the end of the Employment Period for Good Reason,
Executive shall be entitled to receive:

    (i)        The Accrued Rights;

    (ii)        A Severance Benefit pursuant to the terms and conditions set
forth below, and the Company will reimburse the Executive for Executive’s cost
of continuing medical insurance under COBRA (the “Welfare Benefit”) for eighteen
(18) months; and

    (iii)        If the termination of employment occurs during the Initial
Employment Period, any Pro Rata Deferred Bonus which Executive is eligible to
receive pursuant to Section 3.6 hereof.

    (b)        The Company shall pay the Severance Benefit, without interest
thereon, in eighteen (18) substantially equal monthly installments, which
installments shall be payable on the first day of each month, with the first
installment payable in the first full month commencing fifteen (15) days after
the Termination Date. Payment of the Severance Benefit is subject to deductions
for customary withholdings, including, without limitation, federal, state and
local withholding taxes, social security taxes and Medicare taxes. Executive
shall not be under any duty to mitigate damages in order to be eligible to
receive the Severance Benefit.

    (c)        Notwithstanding the foregoing and the terms of Sections
3.5(b)(iii) and 3.6(d), Executive agrees that payment of the Severance Benefit,
the Pro Rata Deferred Bonus and the delivery of any portion of the Restricted
Stock under Section 3.5(b)(iii) is contingent upon the following:

    (i)        In the event of breach by Executive of Sections 5.1 through 5.3
hereof (or any breach of any agreements in the General Release or in the
Nondisclosure and Noncompetition Agreement), Executive shall reimburse the
Company for all compensation or other amounts previously paid, allocated,
accrued, delivered or provided by the Company to Executive pursuant to Section
3.5(b)(ii), 3.6(d) or 4.2 (a) (ii or iii)hereof and the Company shall be
entitled to discontinue the future payment, delivery, allocation, accrual or
provision of the Severance Benefit, the Welfare Benefit, the Pro Rata Deferred
Bonus (if any) and any Restricted Stock.

    (ii)        No later than thirty (30) days after the Termination Date,
Executive must execute and deliver a General Release in the form attached hereto
as Exhibit A.

Following such termination of Executive’s employment hereunder pursuant to this
Section 4.2, Executive shall have no further rights to any compensation or any
other benefits under this Agreement.

        4.3     Termination upon Death. If the Employment Period and Executive’s
employment under this Agreement are terminated due to Executive’s death prior to
the scheduled expiration of the Employment Period, Executive’s estate will
receive:

    (a)        The Accrued Rights; and

    (b)        If the termination of employment occurs during the Initial
Employment Period, any Pro Rata Deferred Bonus which Executive is entitled to
receive pursuant to Section 3.6 hereof and/or any portion of the Restricted
Stock which has vested in accordance with Section 3.5.

Following such termination of Executive’s employment hereunder pursuant to this
Section 4.3, Executive shall have no further rights to any compensation or any
other benefits under this Agreement.

        4.4     Termination for Disability. If the Employment Period and
Executive’s employment under this Agreement is terminated by the Company or by
Executive due to Executive’s Disability prior to the scheduled expiration of the
Employment Period, then Executive will receive:

    (a)        The Accrued Rights; and

    (b)        If the termination of employment occurs during the Initial
Employment Period, any Pro Rata Deferred Bonus which Executive is entitled to
receive pursuant to Section 3.6 hereof and/or any portion of the Restricted
Stock which has vested in accordance with Section 3.5.

Following such termination of Executive’s employment hereunder pursuant to this
Section 4.4, Executive shall have no further rights to any compensation or any
other benefits under this Agreement.

        4.5     Termination by Executive on Account of Retirement. If the
Employment Period and Executive’s employment under this Agreement is terminated
by Executive prior to the scheduled expiration of the Employment Period on
account of Retirement, Executive shall be entitled to receive:

    (a)        The Accrued Rights; and

    (b)        If the termination of employment occurs during the Initial
Employment Period, any Pro Rata Deferred Bonus which Executive is entitled to
receive pursuant to Section 3.6 hereof.

        Following such termination of Executive’s employment hereunder pursuant
to this Section 4.5, Executive shall have no further rights to any compensation
or any other benefits under this Agreement.

      4.6     Expiration of the Employment Period.

    (a)        In the event either party elects not to extend the Employment
Period pursuant to Section 2.2, unless Executive’s employment is earlier
terminated pursuant to Sections 4.1 through 4.5 of this Article IV, Executive’s
term of employment hereunder (whether or not Executive continues as an employee
of the Company thereafter) shall be deemed to close on the close of business on
the day immediately preceding the next scheduled Anniversary Date and Executive
shall be entitled to receive the Accrued Rights.

    (b)        Unless the parties otherwise agree in writing executed subsequent
to the Effective Date, continuation of Executive’s employment with the Company
beyond the expiration of the Employment Period shall be deemed an employment
at-will and, subject only to Section 6.1, shall not be deemed to extend any of
the provisions of this Agreement and Executive’s employment may thereafter be
terminated at will by either Executive or the Company.

Following such termination of Executive’s employment hereunder pursuant to this
Section 4.6, Executive shall have no further rights to any compensation or any
other benefits under this Agreement.

        4.7     Notice of Termination. For purposes of this Agreement, any
purported termination of Executive’s employment by the Company or by Executive,
shall be communicated by written “Notice of Termination” to the other party
hereto in accordance with Section 6.2 hereof. Any Notice of Termination shall
set forth (a) the effective date of termination (for purposes of determining
Executive’s entitlement to benefits hereunder), which shall not be less than
fifteen (15) days after the date the Notice of Termination is delivered (the
“Termination Date”); (b) the specific provision in this Agreement relied upon;
and (c) in reasonable detail, the facts and circumstances claimed to provide a
basis for such termination. If the Company terminates Executive’s employment
pursuant to Section 4.2 or 4.4 hereof, the Termination Date shall be the date
upon which the Company notifies Executive of such termination. If Executive
terminates employment pursuant to Section 4.1, 4.3, 4.4, 4.5 or 4.6 hereof, the
Termination Date shall be Executive’s last full day of work prior to such
termination. Notwithstanding the foregoing, if within fifteen (15) days after
any Notice of Termination is given, the party receiving such Notice of
Termination notifies the other party that a good faith dispute exists concerning
the termination, the “Termination Date” for purposes of determining the
Executive’s entitlement to benefits under this Agreement shall be the date on
which the dispute is finally determined by an independent arbitrator selected by
the American Arbitration Association.

        4.8     Board/Committee Resignation. Upon termination of Executive’s
employment for any reason, Executive agrees to resign, as of the Termination
Date and to the extent applicable, from the Board (and any committees thereof)
and the Board of Directors (and any committees thereof) of any of the Company’s
affiliates.

ARTICLE V
RESTRICTIVE COVENANTS

For the purposes of this Article V, all references to the Company shall include
the Company and its affiliates.

      5.1     Non-Solicitation and Non-Competition.

    (a)        Executive acknowledges and recognizes the highly competitive
nature of the businesses of the Company and its affiliates and accordingly
agrees as follows:

    (i)        During the period of Executive’s employment with the Company and,
for a period of two (2) years after termination of Executive’s employment (the
“Nonsolicit Period”), Executive will not, whether on Executive’s own behalf or
on behalf of or in conjunction with any person, firm, partnership, joint
venture, association, corporation or other business organization, entity or
enterprise whatsoever (“Person”), directly or indirectly solicit or assist in
soliciting in competition with the Company, the business of any client or
prospective client:

    (1)        with whom Executive had personal contact or dealings on behalf of
the Company during the one (1) year period preceding Executive’s termination of
employment;

    (2)        with whom employees reporting to Executive have had personal
contact or dealings on behalf of the Company during the one (1) year immediately
preceding the Executive’s termination of employment; or

    (3)        for whom Executive had direct or indirect responsibility during
the one (1) year immediately preceding Executive’s termination of employment.

    (ii)        During the Nonsolicit Period, Executive will not, whether on
Executive’s own behalf or on behalf of or in conjunction with any Person,
directly or indirectly:

    (1)        solicit or encourage any employee of the Company or its
affiliates to leave the employment of the Company or its affiliates; or

    (2)        hire any such employee who was employed by the Company or its
affiliates as of the date of Executive’s termination of employment with the
Company or who left the employment of the Company or its affiliates coincident
with, or within one year prior to or after, the termination of Executive’s
employment with the Company.

    (iii)        During the Nonsolicit Period, Executive will not, directly or
indirectly, solicit, or encourage to cease to work with the Company or its
affiliates, any consultant then under contract with the Company or its
affiliates.

    (iv)        During the period of Executive’s employment with the Company
and, for a period of one (1) year after termination of Executive’s employment,
if Executive remains in the employ of the Company at least until the expiration
of the Employment Period, or for a period of eighteen (18) months after
termination of Executive’s employment, if Executive’s employment is terminated
(either by Executive or by the Company for any reason whatsoever) prior to the
expiration of the Employment Period (the “Noncompete Period”), Executive will
not directly or indirectly:

    (1)        engage in any business that is, or will be, engaged wholly or
primarily in the business of manufacturing, purchasing, selling or supplying in
the United States any product or service manufactured, purchased, sold, supplied
or provided by the Company or its affiliates, and which is or will be directly
in competition with the business of the Company or its affiliates (including,
without limitation, businesses which the Company or its affiliates have specific
plans to conduct in the future and as to which Executive is aware of such
planning) in the United States (a “Competitive Business”);

    (2)        enter the employ of, or render any services to, any Person (or
any division or controlled or controlling affiliate of any Person) who or which
engages in a Competitive Business;

    (3)        acquire a financial interest in, or otherwise become actively
involved with, any Competitive Business, directly or indirectly, as an
individual, partner, shareholder, officer, director, principal, agent, trustee
or consultant; or

    (4)        interfere with, or attempt to interfere with, business
relationships (whether formed before, on or after the date of this Agreement)
between the Company or any of its affiliates and customers, clients, suppliers,
partners, members or investors of the Company or its affiliates.

    (v)        Notwithstanding anything to the contrary herein, Executive may,
directly or indirectly own, solely as an investment, securities of any Person
engaged in the business of the Company or its affiliates which are publicly
traded on a national or regional stock exchange or on the over-the-counter
market if Executive (i) is not a controlling person of, or a member of a group
which controls, such Person and (ii) does not, directly or indirectly, own 5% or
more of any class of securities of such Person.

      5.2     Confidentiality.

    (a)        Executive acknowledges that the identity of the clients and
customers of the Company, the prices, terms and conditions at, or upon which,
the Company sells its products or provides its services and other non-public,
proprietary or confidential information relating to the business, financial and
other affairs of the Company (including, without limitation, any idea, product,
trade secret, know-how, research and development, software, databases,
inventions, processes, formulae, technology, designs and other intellectual
property; creative or conceptual business or marketing plan, strategy or other
material developed for the Company by Executive; or information concerning
finances, investments, profits, pricing, costs, products, services, vendors,
customers, clients, partners, investors, personnel, compensation, recruiting,
training, advertising, sales, marketing, promotions, government and regulatory
activities and approvals — concerning the past, current or future business,
activities and operations of the Company or its affiliates and/or any third
party that has disclosed or provided any of same to the Company on a
confidential basis) (hereinafter collectively referred to as “Confidential
Information”) are valuable, special unique assets of the Company and that such
Confidential Information, if disclosed to others, may result in loss of business
or other irreparable and consequential damage to the Company.

    (b)        Executive shall hold in fiduciary capacity, for the benefit of
the Company, all Confidential Information and shall not, at any time during the
Employment Period or thereafter (i) retain or use for the benefit, purposes or
account of Executive of any other Person, or (ii) disclose, divulge, reveal,
communicate, share, transfer or provide access to any Person outside the Company
(other than its professional advisers who are bound by confidentiality
obligations), any Confidential Information, without the prior written
authorization of the Company.

    (c)        Notwithstanding the foregoing, the term Confidential Information
shall not include information (i) generally known to the public or the trade
other than as a result of Executive’s breach of this covenant or any breach of
other confidentiality obligations by third parties, (ii) made legitimately
available to Executive by a third party without breach of any confidentiality
obligation, (iii) the release of which is deemed by the Board to be in the best
interest of the Company, or (iv) the disclosure of which is required by
applicable law; provided that Executive shall give prompt written notice to the
Company of such legal requirement, disclose no more information than is so
required, and cooperate with any attempts by the Company to obtain a protective
order or similar treatment.

    (d)        Notwithstanding anything herein to the contrary, any party to
this Agreement (and any employee, representative, or other agent of any party to
this Agreement) may disclose to any and all persons, without limitation of any
kind, the tax treatment and tax structure of the transactions contemplated by
this Agreement and all materials of any kind (including opinions or other tax
analyses) that are provided to it relating to such tax treatment and tax
structure. However, any such information relating to the tax treatment or tax
structure is required to be kept confidential to the extent necessary to comply
with any applicable federal or state securities laws.

    (e)        Upon termination of Executive’s employment with the Company for
any reason, Executive shall (i) cease and not thereafter commence use of any
Confidential Information or intellectual property (including without limitation,
any patent, invention, copyright, trade secret, trademark, trade name, logo,
domain name or other source indicator) owned or used by the Company or its
affiliates, (ii) immediately destroy, delete, or return to the Company, at the
Company’s option, all originals and copies in any form or medium (including
memoranda, books, papers, plans, computer files, letters and other data) in
Executive’s possession or control (including any of the foregoing stored or
located in Executive’s office, home, laptop or other computer, whether or not
Company property) that contain Confidential Information or otherwise relate to
the business of the Company or its affiliates, except that Executive may retain
only those portions of any personal notes, notebooks and diaries that do not
contain any Confidential Information, and (iii) notify and fully cooperate with
the Company regarding the delivery or destruction of any other Confidential
Information of which Executive is or becomes aware.

        5.3     Non-Disparagement. Executive agrees that Executive will not
disparage the Company or its affiliates, or its or their current or former
officers, directors, and employees in any way; further, Executive will not make
or solicit any comments, statements, or the like to the media or to others that
would be considered derogatory or detrimental to the good name or business
reputation of any of the aforementioned entities or individuals; provided, that
this Section does not prohibit statements which Executive is required to make
under oath or which are otherwise required by law, provided that such statements
are truthful and made in a professional manner; further provided that this
Section does not prohibit Executive from making statements which would otherwise
be in violation of this Section, provided such statements are made by Executive
in response to public statements made by the Company, or its authorized
representatives, which are derogatory or detrimental to the good name or
business reputation of the Executive.

        5.4     Acknowledgment of Reasonable Covenants. It is expressly
understood and agreed that Executive and the Company consider the restrictions
and covenants contained herein to be reasonable and enforceable, because, among
other things, (a) Executive will be receiving compensation under this Agreement
or otherwise, (b) there are many other areas in which, and companies for which,
Executive could work in view of Executive’s background, (c) the restrictions and
covenants set forth herein do not impose any undue hardship on Executive, (d)
the Company would not have entered into this Agreement but for the restrictions
and covenants of Executive contained herein, and (e) the restrictions and
covenants contained herein have been made in order to induce the Company to
enter into this Agreement.

        5.5     Modification of the Restrictive Covenants. If, at the time of
enforcement of the restrictive covenants set forth herein, a final judicial
determination is made by a court or arbiter of competent jurisdiction that the
time or territory or any other restriction contained in this Agreement is an
unenforceable restriction against Executive, the provisions of this Agreement
shall not be rendered void but shall be deemed amended to apply as to such
maximum time and territory and to such maximum extent as such court may
judicially determine or indicate to be enforceable. Alternatively, if any court
of competent jurisdiction finds that any restriction contained in this Agreement
is unenforceable, and such restriction cannot be amended so as to make it
enforceable, such finding shall not affect the enforceability of any of the
other restrictions contained herein.

ARTICLE VI
MISCELLANEOUS

        6.1     Survival. Sections 4.1 through 4.8 inclusive (as applicable to
the relevant circumstance of termination only), 5.1 through 5.5 inclusive and
6.1 through 6.14 inclusive shall survive and continue in full force in
accordance with their terms notwithstanding any termination of Executive’s
employment hereunder or termination of the Initial Employment Period or the
Employment Period.

        6.2     Notices. All notices, demands or other communications to be
given or delivered under or by reason of the provisions of this Agreement shall
be in writing and shall be deemed to have been given when delivered personally,
mailed by certified or registered mail, return receipt requested and postage
prepaid, or sent via a nationally recognized overnight courier, or sent via
facsimile to the recipient. Such notices, demands and other communications shall
be sent to the address indicated below:

To the Company:
Express Scripts, Inc. 13900 Riverport Drive Maryland Heights, MO 63403
Attention: Chief Executive Officer
To Executive:
Mr. Thomas M. Boudreau XXXXXXXXXXXX XXXXXXXXXXXX

or such other address or to the attention of such other person as the recipient
party shall have specified by prior written notice to the sending party.

        6.3     Severability. Whenever possible, each provision of this
Agreement shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Agreement is held to be invalid,
illegal or unenforceable in any respect under any applicable law or rule in any
jurisdiction, such invalidity, illegality or unenforceability shall not affect
any other provision or any other jurisdiction, but this Agreement shall be
reformed, construed and enforced in such jurisdiction as if such invalid,
illegal or unenforceable provision had never been contained herein.

        6.4     Complete Agreement. This Agreement constitutes the complete
agreement and understanding between the parties regarding the subject matter
hereof and supersedes and preempts any prior understandings, agreements or
representations by and between the parties, written or oral; provided, however,
this Agreement shall not supersede or modify the terms of the Nondisclosure and
Noncompetition Agreement, and the Options and Restricted Stock shall be subject
to the applicable option and restricted stock notices or agreements. The
applicable provisions of this Agreement amend the terms and provisions of the
Express Scripts, Inc. 2000 Long-Term Incentive Plan to the extent addressed by
this Agreement, as the same may have been amended prior to the date hereof, with
respect to awards covered by this Agreement and made to Executive hereunder.

        6.5     Counterparts. This Agreement may be executed in separate
counterparts, each of which is deemed to be an original and all of which taken
together constitute one and the same agreement.

        6.6     Successors and Assigns. Except as otherwise provided herein, all
covenants and agreements contained in this Agreement shall bind and inure to the
benefit of and be enforceable by the Company and its respective successors and
assigns. Except as otherwise specifically provided herein, this Agreement,
including the obligations and benefits hereunder, may not be assigned to any
party by Executive.

        6.7     No Strict Construction. The language used in this Agreement
shall be deemed to be the language chosen by the parties hereto to express their
mutual intent, and no rule of strict construction shall be applied to this
Agreement.

        6.8     Descriptive Headings. The descriptive headings of this Agreement
are inserted for convenience only and do not constitute a part of this
Agreement.

        6.9     Governing Law. This Agreement shall be governed by and construed
in accordance with the laws of the State of Missouri, without regard to
conflicts of laws principles thereof; provided, however, that issues related to
the Incentive Plan or any grants thereunder shall be resolved in accordance with
the laws of the State of Delaware.

        6.10     Specific Performance. The Company shall be entitled to enforce
its rights under this Agreement specifically, to recover damages and costs
(including reasonable attorneys’ fees) caused by any breach of any provision of
this Agreement and to exercise all other rights existing in its favor. The
Executive agrees and acknowledges that money damages are an inadequate remedy
for any breach of the provisions of this Agreement, including, without
limitation, Sections 5.1 through 5.3 hereof, and that the Company shall be
entitled to apply to any court of law or equity of competent jurisdiction
(without posting any bond or deposit) for specific performance and/or other
injunctive relief in order to enforce or prevent any violations of the
provisions of this Agreement. Further, Executive acknowledges that the
forfeiture provision set forth in the termination provisions hereof shall not be
construed to limit or otherwise affect the Company’s right to seek legal or
equitable remedies it may otherwise have, or the amount damages for which it may
seek recovery, resulting from breach of this Agreement.

      6.11     Amendment and Waiver. The provisions of this Agreement may be
amended and waived only with the prior written consent of the Company and
Executive.

      6.12     Tax Indemnification.

    (a)        Notwithstanding anything to the contrary herein (or any other
agreement entered into by and between Executive and the Company or any incentive
arrangement or plan offered by the Company), in the event that any amount or
benefit paid or distributed to Executive pursuant to this Agreement, taken
together with any amounts or benefits otherwise paid or distributed to Executive
by the Company or any of its subsidiaries (collectively, the “Covered
Payments”), would constitute an “excess parachute payment” as defined in Section
280G of the Code, and would thereby subject Executive to an Excise Tax, the
provisions of this Section 6.12 shall apply.

    (b)        If the aggregate present value (as determined for purposes of
Section 280G of the Code) of the Covered Payments exceeds the amount which can
be paid to Executive without Executive incurring an Excise Tax, but is less than
125% of such amount, then the amounts payable to Executive under this Agreement
(or any other agreement by and between Executive and the Company or pursuant to
any incentive arrangement or plan offered by the Company) may, in the discretion
of the Company, be reduced (but not below zero) to the maximum amount which may
be paid hereunder without Executive becoming subject to the Excise Tax (such
reduced payments to be referred to as the “Payment Cap”). In the event Executive
receives reduced payments and benefits as a result of application of this
Section 6.12, Executive shall have the right to designate which of the payments
and benefits otherwise set forth herein (or any other agreement between
Executive and the Company or any incentive arrangement or plan offered by the
Company) will be received in connection with the application of the Payment Cap.

    (c)        If the aggregate present value of all Covered Payments is equal
to or exceeds 125% of the amount which can be paid to Executive without
Executive incurring an Excise Tax, Executive shall be entitled to receive an
additional amount (the “Tax Reimbursement Payment”) such that the net amount
retained by Executive with respect to such Covered Payments, after deduction of
any Excise Tax on the Covered Payments and any federal, state and local income
tax and Excise Tax on the Tax Reimbursement Payment provided for by this Section
6.12, but before deduction for any federal, state or local income or employment
tax withholding on such Covered Payments, shall be equal to the amount of the
Covered Payments. Such additional amount may be paid by the Company directly to
the applicable taxing authority.

    (d)        Immediately upon a Change in Control, the Company shall notify
Executive of any modification or reduction as a result of the application of
this Section 6.12. In the event Executive and the Company disagree as to the
application of this Section 6.12, the Company shall select a law firm or
accounting firm from among those regularly consulted (during the twelve-month
period immediately prior to the Change in Control that resulted in the
characterization of the Covered Payments as parachute payments) by the Company,
and such law firm or accounting firm shall determine, at the Company’s expense,
the amount to which Executive shall be entitled hereunder (and pursuant to any
other agreements, incentive arrangements or plans), taking into consideration
the application of this Section 6.12, and such determination shall be final and
binding upon Executive and the Company.

        6.13     Executive Representation. Executive hereby represents to the
Company that the execution and delivery of this Agreement by Executive and the
Company and the performance by Executive of Executive’s duties hereunder shall
not constitute a breach of, or otherwise contravene, the terms of any employment
agreement or other agreement or policy to which Executive is a party or
otherwise bound.

        6.14     Cooperation. Each party shall provide reasonable cooperation in
connection with any action or proceeding (or any appeal from any action or
proceeding) which relates to events occurring during Executive’s employment
hereunder.

_________________

--------------------------------------------------------------------------------

        IN WITNESS WHEREOF, the parties hereto have executed this Executive
Employment Agreement as of the date first above written.

THIS CONTRACT CONTAINS A BINDING ARBITRATION PROVISION WHICH MAY BE ENFORCED BY
THE PARTIES.

EXPRESS SCRIPTS, INC.

By: /s/ Barrett Toan                                                       
Name: Barrett Toan Title: Chairman and Chief Executive Officer

EXECUTIVE

By: /s/ Thomas M.Boudreau                                          Name: Thomas
M. Boudreau Title: Senior Vice President and General Counsel

--------------------------------------------------------------------------------

EXHIBIT A

GENERAL RELEASE AND ACKNOWLEDGMENT

        THIS GENERAL RELEASE AND ACKNOWLEDGMENT (the “General Release”) is made
this ___ day of ________, ___________, by Thomas M. Boudreau (the “Executive”)
in favor of Express Scripts, Inc. (the “Company”) pursuant to Section 4.2(c)(ii)
of the Executive’s Employment Agreement dated ______________, 2004 (the
“Agreement”). Unless otherwise defined herein, capitalized terms appearing
herein shall have the meanings given to them in the Agreement.

    1.        General Release of Claims. The Executive, for and on behalf of the
Executive and the Executive’s heirs, beneficiaries, executors, administrators,
successors, assigns, and anyone claiming through or under any of the foregoing,
hereby agrees to, and does, release and forever discharge the Company, and its
agents, officers, employees, successors and assigns, from any and all matters,
claims, demands, damages, causes of action, debts, liabilities, controversies,
judgments and suits of every kind and nature whatsoever, foreseen or unforeseen,
known or unknown, arising out of or relating to any matter whatsoever,
including, without limitation, the Executive’s termination from employment with
the Company, matters arising from the offer and acceptance of the Agreement,
matters relating to employment references or lack thereof from the Company, and
those claims described in paragraph 3 hereof.

    2.        Agreement Not to File Suit. Except as otherwise expressly
permitted in paragraph 3 hereof, the Executive, for and on behalf of the
Executive and the Executive’s beneficiaries, executors, administrators,
successors, assigns, and anyone claiming through or under any of the foregoing,
agrees that he or she will not file or otherwise submit any charge, claim,
complaint, or action to any agency, court, organization, or judicial forum (nor
will the Executive permit any person, group of persons, or organization to take
such action on the Executive’s behalf) against the Company arising out of any
actions or non-actions on the part of the Company prior to or as of the date
hereof arising out of or relating to any matter whatsoever. The Executive
further agrees that in the event that any person or entity should bring such a
charge, claim, complaint, or action on the Executive’s behalf, the Executive
hereby waives and forfeits any right to recovery under said claim and will
exercise every good faith effort (but will not be obliged to incur any expense)
to have such claim dismissed.

    3.        Claims Covered. The charges, claims, complaints, matters, demands,
damages, and causes of action referenced in paragraphs 1 and 2 above include,
but are not limited to:

    (a)        any breach of an actual or implied contract of employment between
the Executive and the Company;

    (b)        any claim of unjust, wrongful, or tortious discharge (including
any claim of fraud, negligence, retaliation for whistleblowing, or intentional
infliction of emotional distress);

    (c)        any claim of defamation or other common-law action;

    (d)        any claims of violations arising under the Civil Rights Act of
1964, as amended, 42 U.S.C.ss.2000e et seq., the Age Discrimination in
Employment Act, 29 U.S.C.ss.621 et seq. (only with respect to claims regarding
acts of discrimination arising prior to the execution of this General Release),
the Americans with Disabilities Act of 1990, 42 U.S.C.ss.12101 et seq., the Fair
Labor Standards Act of 1938, as amended, 29 U.S.C.ss.201 et seq., the
Rehabilitation Act of 1973, as amended, 29 U.S.C.ss.701 et seq., the Missouri
Human Rights Act,ss.213.000 R.S.Mo. et seq., or any other relevant federal,
state, or local statutes or ordinances; provided, however, that for purposes of
the Age Discrimination in Employment Act only, this General Release does not
affect the rights and responsibilities of the Equal Employment Opportunity
Commission (the “EEOC”) to enforce the Age Discrimination in Employment Act, nor
does this General Release prohibit the Executive from filing a charge or
complaint under the Age Discrimination in Employment Act with the EEOC or
participating in any investigation or proceeding conducted by the EEOC;

    (e)        any claims for salary, bonus pay, vacation pay, severance pay or
welfare benefits, other than those payments and benefits specifically provided
in the Agreement; and

    (f)        any other matter whatsoever, whether related or unrelated to
employment matters.

    4.        Claims Excluded. Notwithstanding anything else herein to the
contrary, this General Release shall not:

    (a)        apply to the obligations of the Company described in Sections
3.4, 3.5, 3.6 and Article IV of the Agreement; or

    (b)        affect, alter or extinguish any vested rights that the Executive
may have with respect to any benefits, rights or entitlements under the terms of
any employee benefit programs of the Company to which the Executive is or will
be entitled by virtue of his or her employment with the Company or any of its
subsidiaries, and nothing in this General Release will prohibit or be deemed to
restrict the Executive from enforcing his or her rights to any such benefits,
rights or entitlements; or

    (c)        limit the Executive’s right to indemnification to the extent
provided in the Company’s Certificate of Incorporation and/or bylaws.

    5.        Acknowledgments. By signing this General Release, the Executive
hereby represents, certifies and acknowledges that the Executive:

    (a)        has received a copy of the Agreement and this General Release for
review and study before executing the Agreement;

    (b)        has read the Agreement and this General Release carefully before
signing this General Release;

    (c)        has had sufficient opportunity before signing this General
Release to ask any questions the Executive has about the Agreement or this
General Release and has received satisfactory answers to all such questions;

    (d)        understands the Executive’s rights and obligations under the
Agreement and this General Release;

    (e)        understands that the Agreement and this General Release are legal
documents, and that by signing this General Release the Executive is giving up
certain legal rights including but not limited to rights under the Age
Discrimination in Employment Act, 29 U.S.C. ss. 621 et seq. and the other
matters covered in paragraph 3 hereof;

    (f)        understands and agrees that the execution of this General Release
is a condition precedent, and material inducement to the Company’s provision of
payments made to Executive pursuant to Section 3.5, 3.6 or 4.2 of the Agreement
and such payments, subject to the conditions stated therein, constitute
sufficient additional consideration in exchange for the Executive’s promises and
obligations contained herein;

    (g)        knowingly and voluntarily agreed to accept the payments described
in Section 3.5, 3.6 or 4.2 of the Agreement, subject to the conditions stated
therein, as a full and final compromise, adjustment and settlement of all
potential claims herein described;

    (h)        has been given at least twenty-one (21) days to consider this
General Release and that he or she has been advised to consult with an attorney
about its terms, and if the Executive has executed this General Release prior to
the expiration of the twenty-one (21) day period, that he or she was afforded
the opportunity to consider this General Release for twenty-one (21) days before
executing it and that the Executive’s execution of this General Release prior to
the expiration of such twenty-one (21) day period was his or her free and
voluntary act; and

    (i)        understands that he or she may revoke this General Release within
seven (7) days after he or she signs it and that if the Executive does not
revoke this General Release within that time, this General Release becomes
effective and enforceable by both parties immediately after the expiration of
such seven-day period. The Executive also understands that any revocation must
be in writing and must be received by the Company no later than the close of
business on the seventh day after his or her execution of this General Release.
The Executive acknowledges that the Company has given the Executive enough time
to consult with his or her family and other advisers and to consider whether he
or she should agree to the terms of this General Release.

    6.        Governing Law. The validity, interpretation, construction and
performance of this General Release shall be governed by the laws of the State
of Missouri, without regard to principles of conflicts of laws.

    7.        Severability. If any provision of this General Release or the
application thereof to any person or circumstance shall to any extent be held to
be invalid or unenforceable, the remainder of this General Release shall not be
affected thereby, and each provision of this General Release shall be valid and
enforceable to the fullest extent permitted by law.

    8.        Binding Effect. Executive acknowledges that the terms and
provisions of this General Release shall be binding upon the Executive’s heirs,
executors, administrators, personal representatives, successors and assigns, and
that the terms and provisions of this General Release shall inure to the benefit
of the Company’s affiliates, successors, assigns, officers, directors, agents,
attorneys and employees.

_________________

THIS GENERAL RELEASE HAS IMPORTANT LEGAL CONSEQUENCES, INCLUDING THE EXECUTIVE’S
WAIVER TO PURSUE CERTAIN LEGAL CLAIMS. THE EXECUTIVE IS ADVISED TO CONSULT WITH
AN ATTORNEY PRIOR TO EXECUTING THIS GENERAL RELEASE.

        IN WITNESS WHEREOF, the undersigned has caused this General Release to
be executed and delivered as of the day and year first above set forth.

EXECUTIVE: