EXHIBIT 10.13

                              EMPLOYMENT AGREEMENT

         This Employment  Agreement (this  "Agreement") is made and entered into
as of the 17th day of August,  1999,  between  Concentra  Managed Care,  Inc., a
Delaware corporation (the "Company"), and Daniel J. Thomas ("Executive").

                                   WITNESSETH:

         WHEREAS, Executive desires to continue as President and Chief Executive
Officer of the  Company  and to remain an integral  part of its  management  who
participates  in the  decision-making  process  relative to short and  long-term
planning and policy for the Company; and

         WHEREAS, it is the desire of the Board of Directors of the Company (the
"Board of Directors")  to assure itself of the management  services of Executive
by directly engaging Executive as an officer of the Company and its subsidiaries
and affiliates; and

         WHEREAS,  Executive  is  desirous  of  committing  himself to serve the
Company on the terms herein provided.

         NOW, THEREFORE, in consideration of the foregoing and of the respective
covenants and agreements set forth below, the parties hereto agree as follows:

         1.  EMPLOYMENT AND TERM. The Company hereby agrees to employ  Executive
as its President and Chief  Executive  Officer,  and Executive  hereby agrees to
accept such  employment,  on the terms and conditions set forth herein,  for the
period commencing on the date of the effectiveness of this Agreement pursuant to
Section 14 hereof (the  "Effective  Date") and  expiring as of 11:59 p.m. on the
second   anniversary  of  the  Effective  Date  (unless  sooner   terminated  as
hereinafter set forth) (the "Term"); PROVIDED,  HOWEVER, that commencing on such
second anniversary date, and each anniversary of the date hereof thereafter, the
Term of this Agreement shall  automatically  be extended for one additional year
unless at least  thirty  (30)  days  prior to each such  anniversary  date,  the
Company or Executive shall have given notice that it or he, as applicable,  does
not wish to extend this Agreement.

         2.  DUTIES AND RESTRICTIONS.

             (a) DUTIES AS EMPLOYEE OF THE COMPANY.  Executive shall, subject to
the  supervision  of the Company's  Board of  Directors,  serve as the Company's
President and Chief Executive Officer,  with all such powers as may be set forth
in the Company's Bylaws with respect to, and/or are reasonably incident to, such
officerships.

             (b) OTHER  DUTIES.  Executive  agrees to serve as  requested by the
Company as a director of the Company's subsidiaries and affiliates and in one or
more  executive  offices of any of the Company's  subsidiaries  and  affiliates;
PROVIDED, that the Company indemnifies Executive for serving in any and all such
capacities in a manner acceptable to the Company and Executive.

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Executive  agrees that he shall not be entitled to receive any  compensation for
serving in any capacities of the Company's  subsidiaries  and  affiliates  other
than the  compensation  to be paid to Executive by the Company  pursuant to this
Agreement.

             (c) NONCOMPETITION. Executive agrees that he will not, for a period
of two (2) years  following the  termination of his employment with the Company,
(1) solicit the employment  of,  endeavor to entice away from the Company or its
subsidiaries  or  affiliates or otherwise  interfere  with any person who was an
employee  of or  consultant  to  the  Company  or any  of  its  subsidiaries  or
affiliates  during the one year period  preceding  such  termination,  or (2) be
employed by,  associated  with, or have any interest in,  directly or indirectly
(whether  as  principal,  director,  officer,  employee,  consultant,   partner,
stockholder,  trustee,  manager,  or  otherwise),  any  occupational  healthcare
company or managed care company  which has a principal  line of business that is
directly  competitive  with the Company or its subsidiaries or affiliates in any
geographical  area in which the Company or its subsidiaries or affiliates engage
in business at the time of such  termination  or in which any of them,  prior to
termination  of  Executive's  employment,  evidenced in writing its intention to
engage  in  business.  Notwithstanding  the  foregoing,  Executive  shall not be
prohibited from owning five percent or less of the outstanding equity securities
of any entity  whose  equity  securities  are  listed on a  national  securities
exchange or publicly traded in any over-the-counter market.

             (d)  CONFIDENTIALITY.  Executive shall not, directly or indirectly,
at any time during or  following  the  termination  of his  employment  with the
Company,  reveal,  divulge,  or make known to any  person or entity,  or use for
Executive's personal benefit (including,  without limitation, for the purpose of
soliciting business, whether or not competitive with any business of the Company
or any of its subsidiaries or affiliates),  any information  acquired during the
course of employment hereunder with regard to the financial,  business, or other
affairs of the  Company or any of its  subsidiaries  or  affiliates  (including,
without  limitation,  any list or record of persons or  entities  with which the
Company or any of its  subsidiaries or affiliates has any dealings),  other than
(1)  material  already  in the  public  domain,  (2)  information  of a type not
considered  confidential  by persons  engaged in the same  business or a similar
business to that  conducted by the Company,  or (3) material  that  Executive is
required to disclose under the following  circumstances:  (A) in the performance
by Executive of his duties and responsibilities hereunder,  reasonably necessary
or   appropriate   disclosure   to  another   employee  of  the  Company  or  to
representatives or agents of the Company (such as independent public accountants
and legal counsel); (B) at the express direction of any authorized  governmental
entity;  (C)  pursuant to a subpoena or other court  process;  (D) as  otherwise
required  by  law  or the  rules,  regulations,  or  orders  of  any  applicable
regulatory  body; or (E) as otherwise  necessary,  in the opinion of counsel for
Executive,  to be disclosed by Executive in connection  with the  prosecution of
any legal action or proceeding initiated by Executive against the Company or any
subsidiary  or  affiliate  of the Company or the defense of any legal  action or
proceeding  initiated  against  Executive  in his  capacity  as an  employee  or
director of the Company or any subsidiary or affiliate of the Company. Executive
shall,  at any time  requested  by the  Company  (either  during  or  after  his
employment  with the Company),  promptly  deliver to the Company all  memoranda,
notes, reports,  lists, and other documents (and all copies thereof) relating to
the business of the

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Company or any of its  subsidiaries  or affiliates  which he may then possess or
have under his control.

         3.  COMPENSATION AND RELATED MATTERS.

             (a) BASE SALARY.  Executive shall receive a base salary paid by the
Company  ("Base  Salary") at the annual rate of Four  Hundred  Thousand  Dollars
($400,000) during each calendar year of the Term, payable in substantially equal
monthly  installments  (or such other more  frequent  times as executives of the
Company  normally are paid).  In addition,  the Company's  Board of Directors or
Option and  Compensation  Committee  of the Board of  Directors  shall,  in good
faith,  consider granting  increases in the Base Salary based on such factors as
Executive's  performance and the growth and/or profitability of the Company, but
the Company shall have no obligation to grant such increases in compensation.

             (b) BONUS  PAYMENTS.  Executive  shall be entitled  to receive,  in
addition  to the Base  Salary,  such  bonus  payments,  if any,  as the Board of
Directors or the Option and Compensation Committee of the Board of Directors may
specify.

             (c)  EXPENSES.   During  the  term  of  his  employment  hereunder,
Executive shall be entitled to receive prompt  reimbursement  for all reasonable
expenses  incurred  by him (in  accordance  with  the  policies  and  procedures
established  by the Board of  Directors  for its senior  executive  officers) in
performing  services  hereunder,   provided  that  Executive  properly  accounts
therefor in accordance with Company policy.

             (d) OTHER  BENEFITS.  The Company shall not make any changes in any
employee  benefit  plans or other  arrangements  in effect on the date hereof or
subsequently  in  effect  in  which   Executive   currently  or  in  the  future
participates (including,  without limitation,  each pension and retirement plan,
supplemental pension and retirement plan, savings and profit sharing plan, stock
or unit ownership plan,  stock or unit purchase plan, stock or unit option plan,
life insurance plan,  medical  insurance  plan,  disability  plan,  dental plan,
health-and-accident  plan, or any other similar plan or arrangement)  that would
adversely affect Executive's rights or benefits  thereunder,  unless such change
occurs  pursuant to a program  applicable  to all  executives of the Company and
does not  result in a  proportionately  greater  reduction  in the  rights of or
benefits to  Executive  as compared  with any other  executive  of the  Company.
Executive  shall be entitled to  participate  in or receive  benefits  under any
employee benefit plan or other  arrangement made available by the Company now or
in the future to its senior  executive  officers and key  management  employees,
subject to and on a basis  consistent  with the terms,  conditions,  and overall
administration of such plan or arrangement.  Nothing paid to Executive under any
plan or arrangement presently in effect or made available in the future shall be
deemed  to be in lieu of the  Base  Salary  payable  to  Executive  pursuant  to
paragraph (a) of this Section 3.

             (e)  VACATIONS.  Executive  shall  be  entitled  to ten  (10)  paid
vacation days for the period from the date of this  Agreement  through  December
31, 1999.  Executive shall be entitled to twenty (20) paid vacation days in each
calendar year commencing on or after January 1, 2000, or such additional  number
as may be determined by the Board of Directors  from time to

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time.  For purposes of this Section 3(e),  weekends  shall not count as vacation
days and  Executive  shall also be  entitled to all paid  holidays  given by the
Company to its senior executive officers.

             (f)  PERQUISITES.  Executive  shall  be  entitled  to  receive  the
perquisites and fringe benefits appertaining to senior executive officers of the
Company in accordance  with any practice  established by the Board of Directors.
In  the  event  Executive's  employment  hereunder  is  terminated  (whether  by
Executive  or the  Company) for any reason  whatsoever  (other than  Executive's
death), then the Company shall, at Executive's written request and to the extent
permitted by the terms of such policies and applicable law, assign and convey to
Executive any life insurance  policies  maintained by the Company on the life of
Executive,  who shall thereafter be solely responsible,  at his election, to pay
all  premiums  payable  after such  assignment  and  conveyance  to maintain the
coverage under such policies with respect to Executive.  Executive  shall not be
required  to pay any  money or other  consideration  to the  Company  upon  such
assignment  and  conveyance,  it being  acknowledged  and agreed by the  parties
hereto that Executive's  execution and delivery hereof  constitute  adequate and
satisfactory consideration for such assignment and conveyance.

             (g) PRORATION. Excepting only payments pursuant to Section 3(b) for
calendar year 1999 (which  payments  shall be based upon a full calendar  year),
any  payments  or  benefits  payable to  Executive  hereunder  in respect of any
calendar  year during  which  Executive is employed by the Company for less than
the  entire  year,   unless  otherwise   provided  in  the  applicable  plan  or
arrangement,  shall be  prorated in  accordance  with the number of days in such
calendar year during which he is so employed.

      4. EXECUTIVE'S  OFFICE AND RELOCATION.  Executive shall primarily  perform
his duties and  responsibilities  hereunder at the Company's  offices located at
5080 Spectrum Drive, Addison, Texas, and 312 Union Wharf, Boston,  Massachusetts
(or  at  such  other  location   within  the  Dallas,   Texas,   and/or  Boston,
Massachusetts,  metropolitan  areas,  to which  the  Company  may in the  future
relocate such  principal  executive  offices),  except for  reasonable  required
travel on the Company's  business.  If the Company requests  Executive to report
for the performance of his services hereunder on a regular or permanent basis at
any  location  or office  more  than  thirty-five  (35)  miles  from the  office
locations  described  in the first  sentence  of this  Section 4, and  Executive
agrees to such change, the Company shall pay Executive's  reasonable  relocation
and  moving  expenses,  including,  but not  limited  to, the cost of moving his
immediate family,  expenses incurred while seeking new housing (including travel
by Executive's  spouse) and temporary  living expenses  incurred by Executive or
his family for up to one hundred eighty (180) days.

      5. TERMINATION.  Executive's employment hereunder may be terminated by the
Company or Executive, as applicable,  without any breach of this Agreement, only
under the following circumstances.

             (a) DEATH.  Executive's  employment  hereunder shall terminate upon
his death.

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             (b)  DISABILITY.  If, as a result of Executive's  incapacity due to
physical or mental illness,  Executive  shall have been unable,  with reasonable
accommodation,   to  perform  the   essential   functions   of  his  duties  and
responsibilities  hereunder  on a full time basis for one hundred  eighty  (180)
consecutive  calendar  days, and within thirty (30) days after written notice of
termination  is given  (which  may  occur  before  or after  the end of such one
hundred  eighty  (180) day  period)  Executive  shall not have  returned  to the
performance of his material managerial duties and responsibilities  hereunder on
a full time basis, the Company may terminate Executive's employment hereunder.

             (c) CAUSE.  Subject to the  provisions of Section 7(d), the Company
may terminate  Executive's  employment hereunder for Cause. For purposes of this
Agreement,  the Company shall have "Cause" to terminate  Executive's  employment
hereunder upon:

                  (1) Executive's  willful or intentional  failure to perform or
gross  negligence  in  the  performance  of  Executive's   material  duties  and
responsibilities   hereunder  (other  than  any  such  failure   resulting  from
Executive's  incapacity  due to physical or mental illness or any such actual or
anticipated  failure  after the  issuance  of a Notice of  Termination  for Good
Reason (as hereinafter defined) by Executive);

                  (2) The  commission  by Executive of  dishonesty or fraud of a
material nature in connection with the performance of his duties  hereunder,  or
willful or intentional  misconduct of a material  nature in connection  with the
performance of his duties hereunder;

                  (3) The conviction of Executive,  or the entering of a plea of
nolo contendere by Executive, with respect to a felony;

                  (4)  Unprofessional  or unethical conduct of a material nature
by Executive  in  connection  with the  performance  of his duties  hereunder as
determined in a final  adjudication of any board,  institution,  organization or
governmental  agency  having any  privilege or right to pass upon the conduct of
Executive;

                  (5)  Intentional,  willful,  or grossly  negligent  conduct by
Executive  which  is  materially  detrimental  to  the  reputation,   character,
business, or standing of the Company, including,  without limitation, the use by
Executive of a controlled substance; or

                  (6) The  continued  breach by Executive of any of  Executive's
material obligations under this Agreement.

             (d) TERMINATION BY EXECUTIVE.  Subject to the provisions of Section
7(c), and at his option,  Executive may terminate his  employment  hereunder (1)
for Good Reason and/or for Additional Reason, or (2) if his health should become
impaired  to an  extent  that  makes the  continued  performance  of his  duties
hereunder hazardous to his physical or mental health or his life.

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             For purposes of this  Agreement,  the  termination  of  Executive's
employment  hereunder by Executive  because of the occurrence of any one or more
of the following events shall be deemed to have occurred for "Good Reason":

                  (A) a material  change in the  nature or scope of  Executive's
authorities, status, powers, functions, duties,  responsibilities,  or reporting
relationships  that is  determined  by  Executive in good faith to be adverse to
those existing before such change;

                  (B) any  removal by the  Company  of  Executive  from,  or any
failure to reelect  Executive  to, the  positions  indicated in Section 1 hereof
except in connection  with  termination of  Executive's  employment for Cause or
disability;

                  (C) a  reduction  in  Executive's  Base  Salary  or any  other
failure by the Company to comply with Section 3 hereof that is not  consented to
or approved by Executive;

                  (D) the  relocation  of  Executive's  office at which he is to
perform his duties and  responsibilities  hereunder to a location outside of the
Dallas,  Texas, and Boston,  Massachusetts,  metropolitan areas, or a materially
adverse  alteration in the office space within which Executive is to perform his
duties and  responsibilities  hereunder or in the secretarial and administrative
support provided to Executive; or

                  (E) a failure by the Company or any subsidiary or affiliate of
the Company to comply with any other material term or provision hereof or of any
other written agreement between Executive and the Company or any such subsidiary
or affiliate.

             For purposes of this  Agreement,  the  termination  of  Executive's
employment  hereunder by Executive  because of the occurrence of any one or more
of the following  events within one (1) year following the  consummation  of the
Merger (as defined in that certain  Amended and Restated  Agreement  and Plan of
Merger, dated as of March 24, 1999, between Yankee Acquisition Corp., a Delaware
corporation,  and the Company), shall be deemed to have occurred for "Additional
Reason":

                  (A) the removal of  Executive  from the  position of President
and Chief Executive Officer,  or a material change in the nature or scope of any
of   Executive's   authorities,    status,   powers,   functions,   duties,   or
responsibilities  that is generally an essential  function of such  position and
which is determined  by Executive in good faith to be adverse to those  existing
before such change;

                  (B) a  reduction  in  Executive's  Base  Salary  or any  other
failure by the Company to comply with Section 3 hereof that is not  consented to
or approved by Executive;

                  (C) the  relocation  of  Executive's  office at which he is to
perform his duties and  responsibilities  hereunder to a location outside of the
Dallas,  Texas and Boston,  Massachusetts,  metropolitan  areas, or a materially
adverse  alteration in the office space within which Executive is to perform his
duties and  responsibilities  hereunder or in the secretarial and administrative
support provided to Executive; or

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                  (D) a failure by the Company or any subsidiary or affiliate of
the Company to comply with any other material term or provision hereof or of any
other written agreement between Executive and the Company or any such subsidiary
or affiliate.

     6.  COMPENSATION  UPON TERMINATION OR FAILURE TO RENEW.  Executive shall be
entitled to the following  compensation from the Company upon the termination of
his  employment or upon the Company's  delivery of notice  pursuant to Section 1
that the Term of this Agreement  shall not following any anniversary of the date
hereof be automatically extended for an additional year.

             (a) DEATH. If Executive's  employment shall be terminated by reason
of his death, the Company shall pay to such person as shall have been designated
in a notice filed with the Company prior to  Executive's  death,  or, if no such
person shall be designated, to his estate as a death benefit, his Base Salary to
the  date  of  his  death  in  addition  to  any  payments  Executive's  spouse,
beneficiaries,  or estate may be entitled to receive  pursuant to any pension or
employee benefit plan or other  arrangement or life insurance policy  maintained
by the Company. In addition,  (x) the Company shall make payments of premiums to
continue the medical and dental  insurance  coverage of  Executive's  spouse and
children  under  age  twenty-five  (25) as in  effect  at and as of the  date of
Executive's  death (or to provide as similar  coverage as possible  for the same
premiums if the continuation of existing  coverage is not permitted) for one (1)
year  after  the date of  Executive's  death,  in each case to the  extent  such
coverage is available, and (y) the Company shall make a lump sum cash payment to
the appropriate  insurance  company(ies)  in an amount  sufficient to fully fund
future premium  payments  pursuant to Executive's  then existing  second-to-die,
split-dollar   insurance   policy(ies)   obtained  through  the  Company  and/or
OccuSystems, Inc.

             (b)  DISABILITY.  During any period that Executive fails to perform
his material  managerial  duties and  responsibilities  hereunder as a result of
incapacity  due to  physical  or mental  illness,  Executive  shall  continue to
receive his Base Salary and any bonus payments until  Executive's  employment is
terminated  pursuant to Section 5(b) hereof or until  Executive  terminates  his
employment  pursuant to Section  5(d)(2) hereof,  whichever first occurs.  After
such termination, the Company shall pay to Executive, on or before the fifth day
following the Date of Termination  (as  hereinafter  defined) his Base Salary to
the Date of  Termination.  In addition,  (x) the Company  shall make payments of
premiums as necessary to cause  Executive  and  Executive's  spouse and children
under age  twenty-five  (25) to continue to be covered by the medical and dental
insurance  as in effect at and as of the Date of  Termination  (or to provide as
similar  coverage  as possible  for the same  premiums  if the  continuation  of
existing  coverage  is not  permitted)  for  one  (1)  year  after  the  Date of
Termination,  in each case to the extent such coverage is available, and (y) the
Company  shall  make a lump  sum  cash  payment  to  the  appropriate  insurance
company(ies)  in an amount  sufficient  to fully fund  future  premium  payments
pursuant to  Executive's  then existing  second-to-die,  split-dollar  insurance
policy(ies) obtained through the Company and/or OccuSystems, Inc.

             (c) CAUSE. If Executive's employment shall be terminated for Cause,
the Company shall pay Executive his Base Salary  through the Date of Termination
at the rate in

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effect at  the  time Notice of Termination  is given.  Such payments shall fully
discharge the Company's obligations hereunder.

             (d) BREACH BY THE  COMPANY,  FOR GOOD  REASON,  OR UPON  FAILURE TO
RENEW.  If  (1) in  breach  of  this  Agreement,  the  Company  shall  terminate
Executive's  employment  (it being  understood  that a purported  termination of
Executive's  employment  by the  Company  pursuant  to  any  provision  of  this
Agreement that is disputed and finally  determined not to have been proper shall
be a termination by the Company in breach of this  Agreement),  or (2) Executive
shall  terminate his employment  for Good Reason,  or (3) the Company shall give
Executive  notice  pursuant  to Section 1 prior to any  anniversary  of the date
hereof that the Term of this Agreement shall not be  automatically  extended for
an  additional  year on any such  anniversary  date,  then the Company shall pay
Executive:

                  (A) his Base  Salary  through the Date of  Termination  at the
rate in effect at the time Notice of Termination is given;

                  (B) in lieu of any further  salary  payments to Executive  for
periods  subsequent  to the  Date  of  Termination,  the  Company  shall  pay as
severance  pay to  Executive  on or before the fifth day  following  the Date of
Termination  and on the  fifth  day of  each  of the  twenty-three  (23)  months
thereafter (amounting to a total of twelve (24) months), an amount in cash equal
one-twelfth  (1/12) of  Executive's  annual Base Salary at the rate in effect at
the time the Notice of  Termination is given (for a total of two (2) year's Base
Salary); and

                  (C) all  benefits  payable  under  the  terms of any  employee
benefit plan or other arrangement as of the Date of Termination.

             In  addition,  (x) the Company  shall make  payments of premiums as
necessary to cause  Executive  and  Executive's  spouse and  children  under age
twenty-five  (25) to continue to be covered by the medical and dental  insurance
as in effect at and as of the Date of  Termination  (or to  provide  as  similar
coverage  as possible  for the same  premiums  if the  continuation  of existing
coverage is not  permitted) for one (1) year after the Date of  Termination,  in
each case to the extent such  coverage is  available,  and (y) the Company shall
make a lump sum cash payment to the  appropriate  insurance  company(ies)  in an
amount  sufficient to fully fund future premium payments pursuant to Executive's
then existing second-to-die, split-dollar insurance policy(ies) obtained through
the Company and/or OccuSystems, Inc.

             (e)  MITIGATION.  Executive  shall not be required to mitigate  the
amount of any payment provided for in this Section 6 by seeking other employment
or  otherwise;   PROVIDED,  HOWEVER,  that,  anything  herein  to  the  contrary
notwithstanding, in the event of the termination of Executive's employment prior
to a Change in Control (as defined in the  Concentra  Managed Care,  Inc.,  1997
Long-Term  Incentive Plan) which occurs after the consummation of the Merger (as
defined in that certain Amended and Restated Agreement and Plan of Merger, dated
as of March 24,  1999,  by and  between  Yankee  Acquisition  Corp.,  a Delaware
corporation,  and the Company)  (but not if  Executive's  employment  terminates
after such a Change in Control),  the amount of any payment  pursuant to Section
6(d)(B) and/or  pursuant to the first paragraph of

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Section  6(f) shall be reduced by any  compensation  earned by  Executive as the
result of  employment  by another  employer  (whether  as a  director,  officer,
employee,  manager,  owner,  consultant,   independent  contractor,  advisor  or
otherwise) after the Date of Termination  until the end of the twenty-four month
period of clause (B) of Section 6(d) above.

             (f) ADDITIONAL  REASON. If Executive shall terminate his employment
for Additional Reason, as well as for Good Reason,  then, in addition to and not
in lieu of any  other  amounts  payable  by the  Company  to  Executive  whether
pursuant to Section  6(d) or  otherwise  (it being the  intention of the parties
that,  upon the occurrence of an event or events  described in the definition or
"Good Reason" and "Additional  Reason" in Section 5(d),  Executive may terminate
this  Agreement  for Good Reason AND for  Additional  Reason),  then the Company
shall pay  Executive  as  additional  severance  pay, on or before the fifth day
following the Date of Termination, a lump sum in cash equal to one-half (1/2) of
Executive's  annual  Base Salary at the rate in effect at the time the Notice of
Termination is given (for a total of two and one-half (2 1/2) times  Executive's
full annual Base Salary when combined with amounts  payable  pursuant to Section
6(d)(B)).

             In  addition,  the  Company  shall make  payments  of  premiums  as
necessary to cause  Executive  and  Executive's  spouse and  children  under age
twenty-five  (25) to continue to be covered by the medical and dental  insurance
as in effect at and as of the Date of  Termination  (or to  provide  as  similar
coverage  as possible  for the same  premiums  if the  continuation  of existing
coverage  is not  permitted)  for one (1) year in  addition  to the one (1) year
provided for under Section 6(d) (for a total of two (2) years) after the Date of
Termination, in each case to the extent such coverage is available.

         7.  OTHER PROVISIONS RELATING TO TERMINATION.

             (a)  NOTICE  OF   TERMINATION.   Any   termination  of  Executive's
employment by the Company or by Executive (other than termination because of the
death of Executive)  shall be  communicated  by written Notice of Termination to
the  other  party  hereto.  For  purposes  of  this  Agreement,   a  "Notice  of
Termination"  shall mean a notice which shall indicate the specific  termination
provision in this Agreement relied upon and shall set forth in reasonable detail
the facts and  circumstances  claimed  to  provide  a basis for  termination  of
Executive's employment under the provision so indicated.

             (b) DATE OF TERMINATION.  For purposes of this Agreement,  "Date of
Termination"  shall mean:  (1) if  Executive's  employment  is terminated by his
death,  the date of his  death;  (2) if  Executive's  employment  is  terminated
because of a disability  pursuant to Section  5(b),  then thirty (30) days after
Notice of Termination is given  (provided that Executive shall not have returned
to the  performance  of his duties on a full-time  basis during such thirty (30)
day period);  (3) if  Executive's  employment  is  terminated by the Company for
Cause or by  Executive  for Good  Reason  and/or for  Additional  Reason,  then,
subject  to  Sections  7(c)  and  7(d),  the date  specified  in the  Notice  of
Termination;  (4) if the Company gives  Executive  notice  pursuant to Section 1
prior to any  anniversary  of the date  hereof  that the Term of this  Agreement
shall  not  be  automatically  extended  for an  additional  year  on  any  such
anniversary  date, the date upon which

                                       9



the Term expires;  and (5) if Executive's employment is terminated for any other
reason,  the date on which a Notice of Termination is given.

             (c) GOOD REASON AND/OR ADDITIONAL REASON. Upon the occurrence of an
event described in clauses (A) through (E) of the definition of "Good Reason" in
Section 5(d),  and/or upon the  occurrence of an event  described in clauses (A)
through (D) of the definition of "Additional Reason" in Section 5(d),  Executive
may terminate his employment hereunder for Good Reason and/or Additional Reason,
as  applicable,  within one hundred  eighty  (180) days  thereafter  by giving a
Notice of  Termination  to the  Company  to that  effect.  If the  effect of the
occurrence  of the event  giving rise to Good Reason  and/or  Additional  Reason
under Section 5(d) may be cured,  the Company shall have the opportunity to cure
any  such  effect  for a  period  of  thirty  (30)  days  following  receipt  of
Executive's Notice of Termination. If the Company fails to cure any such effect,
the termination for Good Reason and/or  Additional Reason shall become effective
on the date specified in Executive's  Notice of  Termination.  If Executive does
not give such Notice of  Termination  to the Company,  then this  Agreement will
remain in effect; PROVIDED,  HOWEVER, that the failure of Executive to terminate
this  Agreement for Good Reason and/or  Additional  Reason shall not be deemed a
waiver of  Executive's  right to terminate his employment for Good Reason and/or
Additional Reason upon the occurrence of a subsequent event described in Section
5(d) in accordance with the terms of this Agreement.

             (d) CAUSE.  In the case of any  termination of Executive for Cause,
the Company will give Executive a Notice of Termination describing in reasonable
detail, the facts or circumstances giving rise to Executive's  termination (and,
if  applicable,  the action  required  to cure same) and will  permit  Executive
thirty  (30)  days  to cure  such  failure  to  comply  or  perform.  Cause  for
Executive's  termination will not be deemed to exist until the expiration of the
foregoing  cure period,  so long as Executive  continues to use his best efforts
during  the cure  period  to cure  such  failure.  If  within  thirty  (30) days
following  Executive's  receipt of a Notice of Termination for Cause,  Executive
has not cured the facts or circumstances giving rise to Executive's  termination
for Cause,  then Executive's  termination for Cause shall be effective as of the
date specified in the Notice of Termination.

             (e) INTEREST.  Until paid, all past due amounts required to be paid
by the Company under any provision of this Agreement  shall bear interest at the
highest non-usurious rate permitted by applicable federal, state, or local law.

        8. SUCCESSORS; BINDING AGREEMENT.

             (a) SUCCESSORS.  This Agreement shall be binding upon, and inure to
the  benefit  of,  the  Company,  Executive,  and their  respective  successors,
assigns, personal and legal representatives,  executors, administrators,  heirs,
distributees, devisees, and legatees, as applicable.

             (b)  ASSUMPTION.  The Company will require any  successor  (whether
direct or indirect, by purchase of securities,  merger,  consolidation,  sale of
assets,  or otherwise) to all or substantially  all of the business or assets of
the Company,  by an agreement in form and substance

                                       10



reasonably  satisfactory to Executive, to expressly assume this Agreement and to
agree to perform  this  Agreement in the same manner and to the same extent that
the  Company  would be required  to perform it if no such  succession  had taken
place.   Failure  of  the  Company  to  obtain  such  agreement   prior  to  the
effectiveness  of any such  succession  shall be a breach of this  Agreement and
shall entitle  Executive to compensation from the Company in the same amount and
on the same terms as he would be  entitled to  hereunder  if he  terminated  his
employment for Good Reason (and, if such  succession  occurs on or before August
17,  2000,  in the same  amount and on the same terms as he would be entitled to
hereunder if he terminated his employment  for Additional  Reason),  except that
for  purposes  of  implementing  the  foregoing,  the  date on  which  any  such
succession becomes effective shall be deemed the Date of Termination.

             (c) CERTAIN  PAYMENTS.  If  Executive  should die while any amounts
would still be payable to him  hereunder if he had  continued to live,  all such
amounts,  unless otherwise provided herein, shall be paid in accordance with the
terms of this Agreement to Executive's  devisee,  legatee, or other designee or,
if there be no such designee, to Executive's estate.

     9.  NOTICE.  For  purposes  of this  Agreement,  all  notices and all other
communications  provided for in this Agreement  shall be in writing and shall be
deemed  to have been  duly  given  when (a)  delivered  personally,  (b) sent by
facsimile or similar electronic device and confirmed, (c) delivered by overnight
express, or (d) if sent by any other means, upon receipt.  Notices and all other
communications provided for in this Agreement shall be addressed as follows:

                  If to Executive:

                                         Daniel J. Thomas
                                         4 Stevens Circle
                                         Westwood, Massachusetts  02090

                  If to the Company:

                                         Concentra Managed Care, Inc.
                                         312 Union Wharf
                                         Boston, Massachusetts  02109
                                         Fax No.:  (617) 367-8519
                                         Attention:  Chief Executive Officer

                  With a copy to:

                                         Concentra Managed Care, Inc.
                                         5080 Spectrum Drive
                                         Suite 400, West Tower
                                         Addison, Texas  75001
                                         Fax No.:  (972) 387-1938
                                         Attention:  General Counsel


                                       11



or to such other  address  as either  party may have  furnished  to the other in
writing in accordance herewith.

         10.  MISCELLANEOUS.  No  provision of this  Agreement  may be modified,
waived, or discharged unless such waiver,  modification,  or discharge is agreed
to in a written  instrument  signed by Executive  and the Company.  No waiver by
either party hereto of, or compliance  with,  any condition or provision of this
Agreement  to be  performed  by such  other  party  shall be  deemed a waiver of
similar or  dissimilar  provisions  or conditions at the same or at any prior or
subsequent time. No agreements or representations, oral or otherwise, express or
implied,  with  respect to the  subject  matter  hereof have been made by either
party  which  are not set  forth  expressly  in this  Agreement.  The  validity,
interpretation,  construction,  and  performance  of  this  Agreement  shall  be
governed  by the laws of the  State of  Delaware,  excluding  any  choice-of-law
provisions thereof.

         11.  ATTORNEY  FEES.  All legal fees and costs incurred by Executive in
connection  with  the  resolution  of any  dispute  or  controversy  under or in
connection  with this Agreement  shall be reimbursed by the Company to Executive
as bills for such  services are  presented  by Executive to the Company,  unless
such dispute or  controversy  is found to have been brought not in good faith or
without merit by a court of competent jurisdiction.

         12. VALIDITY.  The invalidity or  unenforceability  of any provision or
provisions of this Agreement shall not affect the validity or  enforceability of
any other  provision  of this  Agreement,  which shall  remain in full force and
effect.

         13.   COUNTERPARTS.   This   Agreement   may  be  executed  in  several
counterparts,  each of which shall be deemed to be an original, but all of which
together will constitute one and the same agreement.

         14. ENTIRE  AGREEMENT;  EFFECTIVENESS.  This  Agreement  shall be of no
force or effect unless and until the  consummation  of the Merger (as defined in
that certain  Amended and  Restated  Agreement  and Plan of Merger,  dated as of
March 24, 1999, by and between Yankee Acquisition Corp., a Delaware corporation,
and the Company,  as such agreement may be amended from time to time); upon such
consummation,  this Agreement shall be in full force and effect.  This Agreement
constitutes the entire agreement between the parties with respect to the subject
matter  hereof  and  supersedes  in all  respects  any and all prior  employment
agreements  and/or severance  protection  letters,  agreements,  or arrangements
between Executive,  on the one hand, and the Company or any other predecessor in
interest  thereto or any of their  respective  subsidiaries,  on the other hand,
which  prior  employment   agreements  and/or  severance   protection   letters,
agreements,  and  arrangements,  if any, are hereby  cancelled and of no further
force or effect.

         15. RIGHT AND OPTION OF COMPANY TO REPURCHASE  SHARES UPON  TERMINATION
OF EMPLOYMENT.

                  (a) In the event that,  prior to an initial public offering of
the Company's  equity  securities,  Executive's  employment  with the Company is
terminated  for any  reason,  the  Company

                                       12




shall thereupon have the right and option,  but not the obligation,  to purchase
from Executive all or any part of the shares of common stock, par value $.01 per
share,  of  the  Company  (the  "Shares")  held  by  Executive  as of  the  date
Executive's employment so ceases at a purchase price equal to the greater of (1)
Sixteen and 50/100 Dollars ($16.50) per Share, and (2) the fair market value (as
hereinafter  defined) of such Shares as of the date  Executive's  employment  so
ceases.

             (b) The  Company  may  exercise  the right and option  provided  in
Section  15(a) above by giving  Executive a written  notice of such  election to
purchase  at any time  within  ninety  (90)  days  after  the  date  Executive's
employment  so ceases.  The closing for the  purchase by the Company of any such
Shares  pursuant to the provisions of said Section 15(a) shall take place at the
offices of the Company on the date specified in such written notice,  which date
shall be a  business  day not later  than  sixty  (60) days  after the date such
notice  is  given.  At such  closing,  Executive  will  deliver  or  cause to be
delivered  such Shares,  duly  endorsed  for  transfer,  against  payment of the
applicable  purchase  price  therefor.  Such purchase  price shall be payable to
Executive  in cash or other  immediately  available  funds.  To the  extent  the
Company  chooses not to exercise  such right and option under said Section 15(a)
to purchase any Shares,  such Shares shall  thereupon cease to be subject to the
provisions of this Section 15.

             (c) For the purposes of this  Agreement,  "fair market  value" of a
Share as of any date shall mean the value of such  stock as  determined  in good
faith by the Board of  Directors of the Company on a basis  consistent  with the
manner of  determining  the fair market value of the Company's  common stock for
purposes of offering the Company's common stock to equity investors.

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
and year first above written.


                                            COMPANY:

                                            CONCENTRA  MANAGED  CARE,  INC.

                                            By: /s/ Richard A.Parr II
                                               ---------------------------------
                                            Name:  Richard A.Parr II
                                            Title: Executive Vice President


                                            EXECUTIVE:

                                            /S/ Daniel J. Thomas
                                            ------------------------------------
                                                Daniel J. Thomas


                                       13