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                                                                   EXHIBIT 10.18

ADMINISTAFF(R)

                            CLIENT SERVICE AGREEMENT

THIS CLIENT SERVICE AGREEMENT ("the Agreement"), is made by and between
Administaff Companies, Inc., ("Administaff"), a Delaware corporation with its
principal place of business at 19001 Crescent Springs Drive, Kingwood, Texas
77339-3802, and MHM Services, Inc.  ("Client").

                                  I. PERSONNEL

Subject to the terms of this Agreement, Administaff agrees to furnish Client,
and Client agrees to engage from Administaff, employees for the job functions
listed in Exhibit A ("Confidential Census").  Client warrants that information
supplied to Administaff concerning the employee functions is accurate.

                             II. TERM OF AGREEMENT

This Agreement shall commence on the date this Agreement is executed and remain
in force and effect for a term of one (1) year ("Initial Term").  Following the
Initial Term, this Agreement shall remain in full force and effect for
successive monthly terms (the "Extended Terms") until either (i) the Agreement
is renewed; or, (ii) the Agreement is terminated.  During the Initial Term, and
any Extended Term of this Agreement, either Administaff or Client may terminate
this Agreement by giving thirty (30) days prior written notice.

                              III. ADMINISTRATION

3.1      There are a number of federal and state statutory, common law and
regulatory provisions which define the employer-employee relationship.
"Employer" status is based upon the function for which the employer-employee
relationship is being considered.

3.2      Administaff is the employer of those persons furnished to Client and
listed on Exhibit A and is liable as such for the following purposes:

         a.      compliance with rules and regulations governing the reporting
                 and payment of all federal and state taxes on payroll wages
                 paid under this Agreement including, but not limited to: (i)
                 federal income tax withholding provisions of the Internal
                 Revenue Code; (ii) state and/or local income tax withholding
                 provisions, if applicable; (iii) Federal Insurance
                 Contributions Act (FICA); (iv) Federal Unemployment Tax Act
                 (FUTA); and (v) applicable state unemployment provisions;

         b.      except as provided in Paragraph 3.4g below, compliance with
                 applicable workers' compensation laws including, but not
                 limited to: (i) procuring workers' compensation insurance;
                 (ii) completing and filing all required reports; and (iii)
                 managing claims;

         c.      compliance with the Consolidated Omnibus Reconciliation Act
                 (COBRA);

         d.      compliance with the Immigration Reform and Control Act (IRCA);

         e.      compliance with the Consumer Credit Protection Act, Title III;

         f.      procuring and providing employee benefits;

         g.      monitoring and transmitting to Client changes in governmental
                 regulations relating to policies and practices governing the
                 employer-employee relationship including, but not limited to,
                 issues such as recruiting, interviewing, testing, selecting,
                 orientation of, training, evaluating, replacing, supervision,
                 disciplining and terminating employees.

3.3      Client is the employer of those persons furnished by Administaff and
listed on Exhibit A and is liable as such for the following purposes:

         a.      compliance with Occupational Safety and Health Administration
                 (OSHA) regulations;

         b.      compliance with Environmental Protection Agency (EPA)
                 regulations and any state and/or local equivalent;

         c.      compliance with government contracting provisions including,
                 but not limited to: (i) Executive Order 11246; (ii) Vocational
                 Rehabilitation Act of 1973; (iii) Vietnam Era Veterans'
                 Readjustment Assistance Act of 1974; (iv) Walsh-Healey Public
                 Contracts Act; (v) Davis-Bacon Act, and (vi) Service Contract
                 Act of 1965;

         d.      compliance with the Fair Labor Standards Act (FLSA);

         e.      compliance with the Worker Adjustment and Retraining 
                 Notification Act (WARN);

         f.      compliance with any professional licensing requirements;

         g.      compliance with any fidelity bonding requirements;


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         h.      professional liability, including but not limited to
                 malpractice or errors and omissions coverage and compliance
                 with any regulation mandating such coverage;

         i.      Section 414(o) of the Internal Revenue Code (avoidance of
                 certain pension and non-pension employee benefits
                 requirements) (except as provided in paragraph 3.4c below);

         j.      assignment to, and ownership of, all intellectual property
                 rights including, but not limited to, inventions, whether
                 patentable or not, and patents resulting therefrom, copyrights
                 and trade secrets and all confidentiality agreements regarding
                 proprietary information.

3.4      Administaff and Client will be considered co-employers ("dual or joint
employers") of those persons furnished to Client by Administaff and listed on
Exhibit A for the following purposes:

         a.      compliance with Title VII of the 1964 Civil Rights Act;

         b.      compliance with the Age Discrimination in Employment Act
                 (ADEA);

         c.      compliance with the Employee Retirement Income Security Act
                 (ERISA) (except as provided by paragraph 3.3i above);

         d.      compliance with the Polygraph Protection Act;

         e.      compliance with the Federal Drug Free Workplace Act and any
                 state and/or local equivalent;

         f.      compliance with state employment discrimination laws
                 including, but not limited to, Article 5221k, Texas Revised
                 Civil Statues;

         g.      employer liability under workers' compensation laws;

         h.      implementation of policies and practices relating to the
                 employer-employee relationship such as recruiting,
                 interviewing, testing, selecting, orientation of, training,
                 evaluating, replacing, supervision, disciplining and
                 terminating employees; and

         i.      selection of fringe benefits, including, but not limited to,
                 holidays, vacation, sick leave, parental leave, military
                 leave, and leave of absence.

3.5      Nothing in paragraphs 3.2, 3.3 or 3.4 above shall be construed to
require either Administaff or Client to provide any of the matters referred to
therein except as provided by law or as otherwise specifically provided by this
contract.

3.6      For the purposes of this Agreement, determination of employer status
for situations not set forth and not contemplated herein shall be made by
mutual agreement of Administaff and Client.


                                IV. SUPERVISION

Administaff shall designate one or more on-site supervisors from among its
employees furnished to Client and listed on Exhibit A.  On-site supervisors
shall direct operational and administrative matters relating to services
provided by Administaff's employees and shall carry out Administaff's policies
and procedures formulated in accordance with Paragraph 3.4h above.


                               V. ENROLLMENT FEE

Client agrees to pay Administaff a non-refundable enrollment fee in the sum
specified in Exhibit B (Client Service Application).  This enrollment fee is
due and payable at the time that this Agreement is signed by Client.

                                 VI. SERVICE FEE

In exchange for the personnel services provided by Administaff hereunder,
Administaff and Client agree as follows:

6.1      The Administaff fee rate percentage is set forth in Exhibit B (Client
Service Application) and is calculated utilizing the data submitted by Client
in Exhibit A. If such information is inaccurate, Client shall immediately agree
to amend Exhibit A to reflect the current information and shall pay, within ten
(10) days notice from Administaff of the error, any additional costs incurred
by Administaff as a result of the inaccuracy.

6.2      Each pay period, Client shall pay Administaff its fee comprised of:
(i) the gross payroll of Administaff employees leased to Client during such pay
period; and, (ii) a service fee equal to the fee rate percentage specified in
Exhibit B multiplied by the actual gross payroll of Administaff employees
furnished to Client during such pay period.

6.3      Administaff shall not adjust the fee rate percentage for Client during
any term of this Agreement except for adjustments made necessary by:

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         (i)     statutory and regulatory changes, including, but not limited
                 to, adjustments to FICA, federal and/or state unemployment
                 taxes and workers' compensation; and/or

         (ii)    changes in the information supplied on Exhibit A (Confidential
                 Census) initiated by Client to the extent that such change,
                 when applied to the recalculation of the fee rate percentage,
                 causes an increase or decrease of at least one fee rate
                 percentage point.

6.4      In addition to the foregoing, during any Extended Term, Administaff
may adjust the fee rate percentage upon thirty (30) days written notice to
Client.

6.5      Any increases in the fee rate percentages for statutory or regulatory
changes in employment taxes, insurance costs or job functions shall be effective
on the date of such statutory or regulatory increase or change.

6.6      Any increase in the fee will be billed with the next effective payroll
and be kept current at all times except for retroactive changes or statutory
and/or regulatory changes known at the time the payroll is billed.

6.7      Any change in the fee rate percentage shall be reflected in a revised
Exhibit B which shall then be made a part of this Agreement.

6.8      The fee provided for by this Agreement shall be due and payable at
least one (1) working day prior to the date of payroll delivery.

6.9      Client shall use a method of payment approved in advance by 
Administaff.

6.10     Client or on-site supervisor shall report to Administaff all time
worked by all Administaff employees furnished to Client each pay period and
shall provide Administaff with written verification of same.

6.11     Client shall notify Administaff within two (2) working days of any
error in billing.

6.12     Client shall reimburse Administaff for services not contemplated by
this Agreement which may be required by Client.

                                 VII. INSURANCE

7.1      Administaff shall furnish, and keep in full force and effect at all
times during the term of this Agreement, worker's compensation insurance
covering all Administaff employees furnished to Client pursuant to the terms of
this Agreement.  Upon written request by Client, Administaff shall furnish a
certificate of insurance verifying such coverage.

7.2      Client shall furnish, and keep in force and effect at all times during
the term of this Agreement, comprehensive general liability insurance including
products/completed operations coverage with minimum limits of $1,000,000 per
occurrence and $2,000,000 aggregate. Client shall cause its insurance carrier
to issue a certificate of insurance to Administaff, Inc. confirming this
coverage and to give not less than thirty (30) days advance notice of
cancellation or material change.

7.3      Client shall furnish, and keep in force and effect at all times during
the term of this Agreement, comprehensive automobile liability insurance
covering all owned, hired and non-owned automobiles with a minimum limit of
$1,000,000 per occurrence combined single limit bodily injury and property
damage liability.  The policy shall also provide uninsured motorists insurance
with a minimum combined single limit of Sixty Thousand Dollars ($60,000.00). In
states where "no fault" laws apply, Personal Injury Protection (P.I.P.) or
equivalent coverage shall be required to meet the requirements of the state.
The client shall cause its insurance carrier to issue a certificate of
insurance to Administaff Inc. confirming this coverage and to give not less
than thirty (30) days advance notice of cancellation or material change.

7.4      Client shall deliver copies of all insurance certificates required
pursuant to this Article signed by authorized representatives of the insurance
companies to Administaff within fifteen (15) days of the commencement date of
this Agreement.

                           VII.I EMPLOYMENT AGREEMENT

Each employee furnished by Administaff to Client and listed on Exhibit A shall
be required to execute an Employment Agreement as set forth in Exhibit C
(Employment Agreement Form) before such employee shall commence the term of
assignment with Client.

                                  IX.  DEFAULT

9.1      Acts of default by Client shall include, but are not limited to:

         a.      failure of Client to pay a fee when due;

         b.      failure of Client to comply within thirty (30) days of any
                 directive of Administaff, when such directive is promulgated or
                 made necessary by: (i) a federal state or local governmental
                 body, department or agency; or (ii) an insurance carrier
                 providing coverage to Administaff and/or its employees;




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         c.      direct payment of taxable wages by Client to Administaff
                 employees for services contemplated by this Agreement;

         d.      commission or omission of any act that usurps any right or
                 obligation of Administaff as an employer of the employees
                 covered by this Agreement; and/or,

         e.      violation by Client of any provision of this Agreement.

9.2      In the event Administaff incurs any expenses, fines and/or liabilities
as a result of an act of default by Client as set forth above, Client shall
reimburse Administaff for all actual expenses, fines and/or liabilities,
including, but not limited to, reasonable attorneys' fees, court costs and any
related expenses.

9.3      In the event that this Agreement is terminated due to a default by
Client, Client shall pay Administaff a sum equal to the fee rate percentage
multiplied by the estimated gross payroll for the remaining contract period as
liquidated damages, but such payment does not release Client from its
obligations under this Agreement, or from liability for future breach of such
obligations.

9.4      Upon an act of default by Client other than under Paragraph 9.1c
above, Administaff shall have the option, in its sole and absolute discretion,
of terminating this Agreement, and in the event Administaff exercises such
option, this Agreement shall terminate on the date written notice of same is
delivered to Client.  In the event, however, of an act of default by Client
under Paragraph 9.1c above, Administaff shall have the option in its sole and
absolute discretion of terminating this Agreement effective on the date of such
act.

                                  X. INDEMNITY

10.1     Client hereby agrees to indemnify defend and hold Administaff harmless
from and against any and all liability, expense (including court costs and
attorneys' fees) and claims for damage of any nature whatsoever, whether known
or unknown and whether direct or indirect, as though expressly set forth and
described herein, which Administaff may incur, suffer, become liable for or
which may be asserted or claimed against Administaff as a result of the acts,
errors or omissions, including negligent acts and statutory violations, of
Client.

10.2     Administaff hereby agrees to indemnify, defend and hold Client
harmless from and against any and all liability, expense (including court costs
and attorneys' fees) and claims for damage of any nature whatsoever, whether
known or unknown and whether direct or indirect, as though expressly set forth
and described herein, which Client may incur, suffer, become liable for or
which may be asserted or claimed against Client as a result of the acts, errors
or omissions, including negligent acts and statutory violations, of
Administaff.

10.3     Client and Administaff expressly agree that the indemnification
provisions of this Agreement shall not be limited to claims, expenses, or
liabilities for which one of them is solely liable, but shall also apply to
claims, expenses and liabilities for which client and Administaff are jointly
and concurrently liable.  In such event, if either of them advances funds in
connection with a claim, expense or liability which is subject to this Article X
in excess of its pro rata share, said party shall be indemnified by the other
party hereto for such excess amounts.


                               XI.  MISCELLANEOUS

11.1     This Agreement may be amended from time to time as agreed by the
parties in writing.  Such amendment shall become effective on the date so
designated when signed by both Administaff and Client.

11.2     Client and Administaff warrant and represent to each other that, prior
to the commencement of this Agreement, no separate agreements or arrangements
exist that would obligate Client or Administaff except as set forth herein.

11.3     Client and Administaff agree to immediately report to each other all
accidents and injuries involving Administaff employees assigned to Client.

11.4     Client agrees to comply, at its sole cost and expense, with any
applicable specific directives promulgated by: (i) a federal, state or local
governmental body, department or agency, (ii) an insurance carrier providing
coverage to Administaff and/or its employees affecting this Agreement, and/or
(iii) Administaff as made necessary by circumstances which currently or
specifically affect Administaff, Client or Administaff's employees.

11.5     This Agreement is between Administaff and Client and creates no
individual rights of Administaff employees as against Client.

11.6     Administaff and Administaff's workers' compensation insurance carrier
shall have the right to inspect Client's premises, including any job site to
which Client assigns Administaff's employees.  To the extent possible, such
inspection shall be scheduled at a mutually convenient time.


                               XII.  ARBITRATION

12.1     Administaff and Client agree and stipulate that all claims, disputes
and other matters in question between Administaff and Client arising out of, or
relating to this Agreement or the breach thereof will be decided by arbitration
in accordance with the Federal Arbitration Act (9 U.S.C. Sections 10 and 11)
and the Commercial Arbitration Rules of the American Arbitration Association
then obtaining subject to the limitations of this Article XII.  This agreement
to so arbitrate and any other agreement or consent to arbitrate entered into in
accordance herewith as provided in this Article XII will be specifically
enforceable under the prevailing law of any court having jurisdiction.


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12.2     Notice of the demand for arbitration will be filed in writing with the
other party to the Agreement and with the American Arbitration Association.
The demand for arbitration shall be made within a reasonable time after the
claim, dispute or other matter in question has arisen, and in no event shall
any such demand be made after the date when institution of legal or equitable
proceedings based on such claim, dispute or other matter in question would be
barred by the applicable statute of limitations.

12.3     No arbitration arising out of, or relating to, this Agreement shall
include by consolidation, joinder or in any other manner any other person or
entity who is not a party to this contract unless:

         a.      the inclusion of such other person or entity is necessary if
                 complete relief is to be afforded among those who are already
                 parties to the arbitration, and/or such other person or entity
                 is substantially involved in a question of law or fact which
                 is common to those who are already parties to the arbitration
                 and which will arise in such proceedings; and,

         b.      the written consent of the other person or entity sought to be
                 included and Administaff and Client has been obtained for such
                 inclusion, which consent shall make specific reference to this
                 paragraph; but no such consent shall constitute consent to
                 arbitration of any dispute not specifically described in such
                 consent or to arbitration with any party not specifically
                 identified in such consent.

12.4     The award rendered by the arbitrators will be final, judgment may be
entered upon it in any court having jurisdiction thereof, and will not be
subject to modification or appeal except to the extent permitted by Sections 10
and 11 of the Federal Arbitration Act (9 U.S.C. Sections 10 and 11).

                               XIII.  ASSIGNMENT

Neither party shall assign this Agreement or its rights and duties hereunder,
or any interest herein, without the prior written consent of the other party.

                             XIV.  ATTORNEYS' FEES

The prevailing party in any enforcement action arising in respect to this
Agreement shall be entitled to recover from the other party all costs of such
enforcement action including, without limitation, reasonable attorneys' fees,
court costs and related expenses.

                               XV. GOVERNING LAW

EXCEPT FOR ARTICLE XII OF THIS AGREEMENT, WHICH SHALL BE GOVERNED BY THE
FEDERAL ARBITRATION ACT (9 U.S.C. Sections 10 AND 11), THIS AGREEMENT SHALL
BE GOVERNED BY THE LAWS OF THE STATE OF TEXAS.

                             XVI.  ENTIRE AGREEMENT

This instrument, including the Exhibits attached hereto, contains the entire
Agreement of the parties and supersedes all prior and contemporaneous
agreements or understandings, whether written or oral, with respect to the
subject matter hereof. No amendment or modification hereto shall be valid unless
in writing and signed by both parties hereto.

                              XVII.  SEVERABILITY

If any provision of this Agreement or any amendment thereof, should be invalid,
the remaining provision shall remain in effect and be so construed as to
effectuate the intent and purposes of this Agreement and any amendments
thereto.

                                XVIII.  NOTICES

All notices, requests and communications provided hereunder shall be in writing,
and hand delivered or mailed by United States registered, certified, or express
mail, return receipt requested, and addressed to the party's principal place of
business as set forth in this Agreement adjacent the signature of each party
(or to such other address provided in writing by such party).

                                  XIX.  WAIVER

The waiver by either party hereto of a breach of any term or provision of this
Agreement shall not operate or be construed as a waiver of a subsequent breach
of the same provision by any party or of a breach of any other term or
provision of this Agreement.

                                  XX. EXHIBITS

The following exhibits are attached to this Agreement and incorporated herein
by reference for all purposes:

A.       Exhibit A ("Confidential Census");




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B.       Exhibit B ("Client Service Application"); and,

C.       Exhibit C ("Employment Agreement Form").

D.       ADDENDUM TO CLIENT SERVICE AGREEMENT DATED 6/30/96 [initials]

THIS AGREEMENT is duly executed this 30 day of June, 1996.


FOR CLIENT:        MHM Services, Inc.              ADMINISTAFF COMPANIES, INC.
           --------------------------------        19001 Crescent Springs Drive
                 (Company Name)                    Kingwood, Texas 77339-3802  
                                                   (713) 358-8986              
                                                                               
By: /s/ MICHAEL S. PINKERT 
   ----------------------------------------
   (Signature)              President              By:  /s/ A. STEVE ARIZOF
                                                      --------------------------
         Michael S. Pinkert                                       Vice-President
   ----------------------------------------
   (Name - Typed or Printed)

Address:  7601 Lewisville Road
         ----------------------------------
          McLean, VA 22102
         ----------------------------------

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

Tel. No.:  703-749-4610
         ----------------------------------
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                                    ADDENDUM

         This Addendum is attached to and made a part of that certain Client
Service Agreement (the Agreement) of even date, between Administaff Companies,
Inc. (Administaff), and MHM SERVICES, INC. (Client).  In the event of a conflict
between this Addendum and the Agreement, this Addendum shall control.


ARTICLE I. PERSONNEL

         Article I. Personnel, shall be amended to read as follows:

         "Subject to the terms of this Agreement, Administaff agrees to furnish
         Client, and Client agrees to engage form Administaff, employees for
         the job classifications listed, by workers' compensation
         classification codes, in Exhibit A ("Confidential Census").  Client
         warrants that information supplied to Administaff concerning the codes
         applicable to an employee is accurate."


ARTICLE II. TERM OF AGREEMENT

         Article II, shall be amended to read as follows:

         "This Agreement shall commence on June 30, 1996 and shall remain in
         force and effect until terminated as provided for herein.  Either
         Administaff or Client may terminate this Agreement by giving thirty
         (30) days prior written notice."


ARTICLE III.  ADMINISTRATION

         Article III, Administration, shall be amended to read as follows:

         "3.1    Administaff and Client recognize that there are a number of
         federal and state statutory, common law and regulatory provisions
         which define the employer-employee relationship.  It is the intent of
         Administaff and Client that to the extent permitted by law, 
         "employer" status with respect to an employee furnished to Client by
         Administaff shall be determined as set forth in paragraphs 3.2, 3.3,
         3.4, and 3.7 and if not so determined, shall be based upon the
         function for which the employer-employee relationship is being
         considered and shall be determined in accordance with paragraph 3.6.

         "3.2    Administaff is the employer of those persons furnished to 
         Client and is liable as such for the following purposes:

                 "a.      compliance with rules and regulations governing the
                          reporting and payment of all federal and state taxes
                          on payroll wages paid under this Agreement including,
                          but

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                          not limited to: (i) federal income tax withholding
                          provisions of the Internal Revenue Code; (ii) state
                          and/or local income tax withholding provisions, if
                          applicable; (iii) Federal Insurance Contributions Act
                          (FICA); (iv) Federal Unemployment Tax Act (FUTA); and
                          (v) applicable state unemployment provisions;

                 "b.      except as provided in Paragraph 3.4 g., below,
                          compliance with applicable workers' compensation laws
                          including, but not limited to: (i) procuring workers'
                          compensation insurance; (ii) completing and filing
                          all required reports; and (iii) managing claims;

                 "c.      compliance with the Consolidated Omnibus
                          Reconciliation Act (COBRA);

                 "d.      compliance with the Immigration Reform and Control
                          Act (IRCA);

                 "e.      compliance with the Consumer Credit Protection Act,
                          Title III;

                 "f.      procuring and providing employee benefits;

                 "g.      monitoring and transmitting to Client changes in
                          governmental regulations relating to policies and
                          practices governing the employer-employee
                          relationship including, but not limited to, issues
                          such as recruiting, interviewing, testing, selecting,
                          orientation of, training, evaluating, replacing,
                          supervision, disciplining and terminating employees.

         "3.3  Client is the employer of those persons furnished by 
         Administaff and is liable as such for the following purposes:

                 "a.      compliance with Occupational Safety and Health
                          Administration (OSHA) regulations,

                 "b.      compliance with Environmental Protection Agency (EPA)
                          regulations and any state and/or local equivalent;

                 "c.      compliance with government contracting provisions
                          including, but not limited to: (i)  Executive Order
                          11246; (ii) Vocational Rehabilitation Act of 1973;
                          (iii) Vietnam Era Veterans' Readjustment Assistance
                          Act of 1974; (iv) Walsh-Healy Public Contracts Act;
                          (v) Davis-Bacon Act; and (vi) Service Contract Act of
                          1965;

                 "d.      compliance with the Fair Labor Standards Act (FLSA);

                 "e.      compliance with the Worker Adjustment and Retraining
                          Notification Act (WARN); provided, however, that so
                          long as Client is an employer of less than the

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                          number of employees required to make Client subject
                          to the application of WARN, and if Client would not
                          otherwise be subject to the jurisdiction or
                          application of WARN but for the fact that Administaff
                          is an employer of more than the jurisdictional
                          minimum number of employees required for the
                          compliance with WARN then Administaff shall be
                          responsible for compliance with WARN, in which case
                          Client covenants and agrees that it shall give
                          Administaff no less than ninety (90) days notice of
                          (i) the closing or shut down of an employment site
                          (or one or more facilities or operating units within
                          an employment site) resulting in an employment loss
                          for fifty (50) or more employees during any thirty
                          (30) day period; (ii) the mass layoff of employees
                          which does not result in the closing or shut down of
                          an employment site but which will result in the loss
                          of employment during any thirty (30) day period for
                          500 or more employees, or for 50 to 499 employees if
                          they make up at least 33% of the work force; or (iii)
                          any combination of the closing of an employment site
                          or mass layoff of employees which would not
                          individually trigger the WARN notice requirement if
                          it occurred within a thirty (30) day time period, but
                          which taken together during any ninety (90) day time
                          period reaches the threshold level of employment loss
                          that would require Administaff to give notice;

                 "f.      compliance with any professional licensing 
                          requirements;

                 "g.      compliance with any fidelity bonding requirements;

                 "h.      professional liability, including but not limited to
                          malpractice or errors and omissions coverage and
                          compliance with any regulation mandating such
                          coverage;

                 "i.      Section 414(o) of the Internal Revenue Code
                          (avoidance of certain pension and non-pension
                          employee benefit requirements)(except as provided in
                          paragraph 3.4c below);

                 "j.      the rendering of professional medical services,
                          including, but not by way of limitation, the services
                          of a psychologist and the diagnosis and treatment of
                          all patients under the Client's care; it being
                          specifically acknowledged and agreed that
                          Administaff's duties, responsibilities and functions
                          hereunder shall be administrative and managerial in
                          nature only, and that notwithstanding any other
                          provision of this Agreement to the contrary,
                          Administaff shall engage in no activity hereunder
                          that would constitute the corporate practice of
                          medicine as defined by applicable laws in any
                          jurisdiction in which the corporate practice of
                          medicine is prohibited.  The parties understand and
                          agree that Client has the sole responsibility for the
                          coordination and provision of all medical services
                          and Administaff shall not interfere in any way with
                          the exercise of the professional medical judgment of
                          Client or Client's providers in connection with their
                          practice of medicine.  All of Client's policies and

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<PAGE>   10
                          procedures relating to the governance of its
                          physicians or psychologists who will work under the
                          direction of Client or its physicians or
                          psychologists shall be adopted from time to time in
                          the sole discretion of Client, its shareholders and
                          board of directors, as applicable.  Such policies may
                          include practice standards, peer review and
                          corrective action, disciplinary matters, on-call
                          schedules, referral physician panel and services,
                          clinical procedures, utilization management and
                          quality management procedures, credentialing,
                          appointment and replacement of Association medical
                          directors, patient care decisions, physician and
                          other licensed health care professional compensation
                          and incentives, physician training, continuing
                          education, development and supervision and
                          shareholder eligibility.  Should any function
                          assigned to Administaff hereunder be construed to be
                          within the practice of medicine such that, if
                          performed by Administaff, it would be violative of
                          applicable prohibitions on the corporate practice of
                          medicine, such function thereafter shall be assigned
                          to and become the responsibility of Client and any
                          such prior activities which were undertaken by
                          Administaff shall be considered to have been
                          undertaken by Client.

         "3.4  Administaff and Client will be considered co-employers ("dual 
         or joint employers") of those persons furnished to Client by 
         Administaff for the following purposes:

                 "a.      compliance with Title VII of the 1964 Civil Rights 
                          Act;

                 "b.      compliance with the Age Discrimination in Employment
                          Act (ADEA);

                 "c.      compliance with the Employee Retirement Income
                          Security Act (ERISA) (except as provided by paragraph
                          3.3i above);

                 "d.      compliance with the Polygraph Protection Act;

                 "e.      compliance with the Federal Drug Free Workplace Act
                          and any state and/or local equivalent;
 
                 "f.      compliance with state employment discrimination laws;

                 "g.      employer liability under workers' compensation laws;

                 "h.      implementation of policies and practices relating to
                          the employer-employee relationship such as
                          recruiting, interviewing, testing, selecting,
                          orientation of, training, evaluating, replacing,
                          supervision, disciplining and terminating employees;
                          and



                                     Page 4
<PAGE>   11
               "i.        selection of fringe benefits, including, but not
                          limited to, holidays, vacation, sick leave, parental
                          leave, military leave, and leave of absence.

         "3.5  Nothing in paragraphs 3.2, 3.3, 3.4, or 3.7 shall be construed
         to require either Administaff or Client to perform any matter not
         referred to therein; provided that the foregoing shall not affect the
         obligation of Administaff or Client to perform any matter required by
         law or as otherwise specifically provided by this Agreement.

         "3.6  For purposes of this Agreement, determination of employer status
         for situations not set forth and not contemplated herein shall be made
         by mutual agreement of Administaff and Client.

         "3.7  Client is the employer of those persons furnished by Administaff
         (i) with respect to the assignment and ownership of all intellectual
         property rights including, but not limited to, inventions, whether
         patentable or not, and patents resulting therefrom, copyrights and
         trade secrets; and (ii) with respect to any confidentiality agreements
         regarding proprietary information and any covenant not to compete."


ARTICLE VI.  SERVICE FEE

         Article VI., Service Fee, Paragraph 6.3(i) shall be amended to read as
         follows:

         "6.3  ADMINISTAFF shall not adjust the fee rate percentage for Client
         more often than once annually during the term of this Agreement except
         for adjustments made necessary by:

                 "(i)     statutory and regulatory changes including, but not
                          limited to, adjustments to FICA and federal and/or
                          state unemployment taxes and workers' compensation;
                          and/or;

                 "(ii)    changes in the information supplied on Exhibit A
                          (Confidential Census) initiated by Client to the
                          extent that such change, when applied to the
                          recalculation of the fee rate percentage, causes an
                          increase or decrease of at least one fee rate
                          percentage point."

         Article VI., Paragraph 6.5 shall be amended to read as follows:

         "6.5  Any increases in the fee rate percentages for statutory or
         regulatory changes in employment taxes, insurance costs or job
         functions shall be effective on the date of such statutory or
         regulatory increase or change.  Any such increase shall be no greater
         than the amount necessary to cover the cost to Administaff of the
         increase in employment taxes, insurance costs, or costs resulting from
         the change in job functions."





                                     Page 5
<PAGE>   12
         Article VI., Paragraph 6.8, shall be amended to read as follows:

         "6.8  The fee provided for by this Agreement shall be due and payable
         at least one (1) working day prior to the date of payroll delivery.
         So long as Client is timely in the reporting of payroll information
         and payment of the fee provided for by this Agreement Administaff
         shall make payroll delivery to the employees furnished to the Client
         on the regularly scheduled payday.  In addition Administaff shall
         provide Client on each payday with a report of the accrued leave for
         each employee furnished to Client (including the leave currently
         accrued by each employee while employed by Client prior to the
         effective date of this Agreement, provided that such information is
         timely and accurately provided to Administaff by Client for inclusion
         on the payday accrued leave report)."


ARTICLE VII.  INSURANCE

         "7.1  Administaff shall furnish and keep in full force and effect at
         all times during the term of this Agreement, workers' compensation
         insurance covering all Administaff employees furnished to Client
         pursuant to the terms of this Agreement.  Upon written request by
         Client, Administaff shall furnish a certificate of insurance verifying
         such coverage.  Such workers' compensation coverage will comply with
         applicable law."


ARTICLE IX.  DEFAULT

         Article IX., Default, Paragraph 9.3 shall be amended to read as
         follows:

         "9.3  In the event that this Agreement is terminated due to a default
         by Client, Client shall pay Administaff a sum equal to the fee rate
         percentage multiplied by the estimated gross payroll for a thirty day
         period as liquidated damages, but such payment does not release Client
         from its obligations under this Agreement, or from liability for
         future breach of such obligations."

         Article IX., Default, shall be amended to add Paragraphs 9.5, 9.6, and
         9.7 as follows:

         "9.5    Acts of default by Administaff shall include, but are not
         limited to:

                 "a.      failure to pay wages to leased employees;

                 "b.      failure to pay payroll taxes to a federal, state, or
                          local governmental body, department or agency when
                          due;

                 "c.      failure to pay premiums to an insurance carrier
                          providing coverage to Administaff employees leased to
                          Client;

                 "d.      violation by Administaff of any provision of this 
                          Agreement."

                                     Page 6
<PAGE>   13
         "9.6    Upon an act of default by Administaff, Client shall have the
         option, in its sole and absolute discretion, of terminating this
         Agreement, and in the event Client exercises such option, this
         Agreement shall terminate on the date written notice of same is
         delivered to Administaff."

         "9.7    In the event Client incurs any expenses, fines and/or
         liabilities as a result of an act of default by Administaff as set
         forth above, Administaff shall reimburse Client for all actual
         expenses, fines and/or liabilities, including, but not limited to,
         reasonable attorneys' fees, court costs and any related expenses."


ARTICLE X.   INDEMNITY

         Article X., Indemnity, Paragraph 10.3, shall be amended to read as
         follows:
          
         "10.3   Client and Administaff expressly agree that the
         indemnification provisions of this Agreement shall not be limited to
         claims, expenses, or liabilities for which one of them is solely
         liable, but shall also apply to claims, expenses and liabilities for
         which Client and Administaff are jointly or concurrently liable.  In
         such event, if either of them advances funds or makes any other
         payment in connection with a claim, expense or liability which is
         subject to this Article X in excess of its pro rata share, said party
         shall be indemnified by the other party hereto for such excess
         amounts."


ARTICLE XI.  MISCELLANEOUS

         Article XI., Miscellaneous, Paragraph 11.2, shall be amended to read
         as follows:

         "11.2   Client and Administaff warrant and represent to each other
         that, prior to the commencement of this Agreement, no separate
         agreements or arrangements exist between the parties that would
         obligate Client or Administaff except as set forth herein."

         Article XI., Miscellaneous, Paragraph 11.4 shall be amended to read as
         follows:

         "11.4   Client agrees to comply, at its sole cost and expense, with
         any applicable specific directives promulgated by: (i) a federal,
         state, or local governmental body, department, or agency, (ii) an
         insurance carrier providing coverage to Administaff and/or its
         employees affecting this Agreement and/or, (iii) Administaff as made
         necessary by circumstances which currently or specifically affect
         Administaff, Client or Administaff's employees except where such
         compliance is otherwise the responsibility of Administaff under the
         terms of this Agreement."





                                     Page 7
<PAGE>   14
         Article XI., Miscellaneous, shall be amended to add Paragraph 11.7 as
         follows:

         "11.7  Administaff hereby warrants that (i) the scope of benefits
         available to eligible employees under the Administaff Benefit Plan
         (the Administaff Plan) on the effective date of this Agreement are
         substantially the same as are stated in the attached pamphlet entitled
         Outline of Benefits attached; (ii) Administaff will give notice of any
         material change in the Administaff Plan to all eligible participants
         at least thirty-five (35) days prior to the effective date of such
         material change; (iii) pre-existing conditions are covered by the
         Major Medical Plan (the Administaff Medical Plan) which is part of the
         Administaff Plan; (iv) amounts paid by a covered employee to defray a
         covered expense under the Client's existing health or medical benefit
         plan (Client's Plan) toward the deductible or co-payment requirements
         of Client's Plan will be credited and apply to the satisfaction of the
         deductible or co-payment requirement of the Administaff Medical Plan
         provided that the amount paid otherwise satisfies the criteria for
         credit or application to the satisfaction of the deductible or
         co-payment requirements of the Administaff Medical Plan and its usual
         proof of payment criteria; and (v) a former employee of Client which
         is covered by COBRA under Client's Plan on the effective date of this
         Agreement will be eligible for COBRA coverage under Administaff's
         Medical Plan provided that Client has fully disclosed the scope and
         extent of such existing COBRA coverage to Administaff prior to the
         execution of this Agreement."


XVI.     ENTIRE AGREEMENT

         Article XVI., Entire Agreement, shall be amended to read as follows:

         "This instrument, including the Exhibits attached hereto, contains the
         entire Agreement of the parties and supersedes all prior and
         contemporaneous agreements or understandings, whether written or
         oral, with respect to the subject matter hereof. No amendment or
         modification hereto shall be valid unless in writing and signed by
         both parties hereto other than changes to Exhibit A (Confidential
         Census) from time to time as may be necessary in the operation of
         Client's business and the performance of the parties of their
         respective obligations under this Agreement."

         This Addendum is executed and effective of even date with the Client
Service Agreement dated June 30, 1996 between the parties hereto to which it is
attached and incorporated by reference.

ADMINISTAFF COMPANIES, INC.              MHM SERVICES, INC.
                                         
By:  /s/ A. STEVE ARIZOF                 By:  /s/ MICHAEL PINKERT 
   -------------------------------          -------------------------------
                    Vice President                                President

 A. Steve Arizof
----------------------------------       ----------------------------------
Name: Typed or Printed                   Name: Typed or Printed


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