<PAGE>

                               FIRST AMENDMENT TO
                              EMPLOYMENT AGREEMENT

         THIS FIRST AMENDMENT TO EMPLOYMENT AGREEMENT is dated as of January 18,
2001, between CORE, INC., a Massachusetts Corporation (hereinafter called "CORE"
or the "Company"), and George C. Carpenter IV (hereinafter called "Executive").

         WHEREAS, Executive is presently an employee and officer of the Company;

         WHEREAS, the Company and Executive entered into an Employment Agreement
dated as of July 15, 1999 (the "Agreement"); and

         WHEREAS, the Company and Executive each desire to enter into this First
Amendment to Employment Agreement concerning Executive's continuing employment
with the Company;

         NOW, THEREFORE, in consideration of the mutual covenants herein
contained, and for other good and valuable consideration, the receipt of which
is acknowledged by both parties hereto, the Company and Executive agree as
follows:

         1. Section 8 of the Agreement is hereby amended by adding the following
Section 8(g) to the end of such Section 8:

         " (g) TERMINATION BY EXECUTIVE FOR GOOD REASON FOLLOWING A CHANGE IN
         CONTROL. Within twelve months following a Change in Control (as defined
         in Section 8(f)), Executive may terminate employment hereunder for Good
         Reason (as defined below) upon thirty (30) days prior written notice to
         the Company, in which event Executive's employment hereunder shall
         terminate and Executive shall be entitled to the following payments:

                  (i) all amounts accrued and unpaid to Executive through the
         termination date, including unpaid salary, pro-rated earned bonus (if
         any), benefits and accrued and unused vacation and sick time; and

                  (ii) severance payments comprising salary and health care
         benefits continuing for 18 months from the date of termination
         (provided such payments shall be reduced to reflect any salary,
         consulting fees or other compensation received by Executive for
         services rendered after one year from the termination date and
         Executive shall timely report to CORE any such compensation), such
         salary continuation payments to be made bi-weekly, or otherwise
         consistent with CORE's payroll policies and shall be subject to
         applicable federal, state and local payroll tax deductions and
         withholdings.

<PAGE>

                  Notwithstanding the requisite 30 day notice period in
         Executive's notice, the Company may elect to have Executive's services
         terminate immediately, provided the Company pays Executive compensation
         and benefits during the period after written notice has been delivered
         and prior to the effective termination date.

                  For the purposes of this Agreement "Good Reason" shall mean
         the occurrence (without Executive's express written consent), of any of
         the following acts by the Company, unless such act is corrected by the
         Company prior to the date of termination specified in the notice of
         termination given by Executive in respect thereof:

                           (i) the assignment to Executive of any duties
                  substantially inconsistent with Executive's status as an
                  executive officer of CORE, a substantial alteration in the
                  nature or status of Executive's title and duties as set forth
                  in Section 1 and 2, a diminution in Executive's duties or the
                  assignment to a position of lesser authority or responsibility
                  than Executive had prior to the Change in Control;

                           (ii) any material breach by the Company of any
                  material provision of this Agreement;

                           (iii) any purported termination by the Company of
                  Executive's employment which is effected other than as
                  provided in this Agreement; or

                           (iv) the requirement that Executive be based at any
                  office or location other than one within a fifty (50) mile
                  radius of CORE's facilities in Irvine, California."

         2. Except as otherwise expressly provided herein, all provisions of the
Agreement shall remain in full force and effect.

         IN WITNESS WHEREOF, the parties hereto have caused this First Amendment
to Employment Agreement to be duly executed as an instrument under seal and
attested, all as of the day and year first above written.

                                   CORE, INC.


                                   By: /s/ William E. Nixon
                                       ---------------------------------
                                   Title: EVP & CFO



                                   /s/ George C. Carpenter IV
                                   -------------------------------------
                                   George C. Carpenter IV
                                  ("Executive")