FIRST AMENDMENT TO STOCK PURCHASE AGREEMENT

“Purchase Price” ), payable in cash at Closing.  Of such amount, (i) One Million Dollars ($1,000,000) has been deposited as the Hard Money Amount, as defined below, to be released to the Prospect Parties as described in Section 1.6(a) below, and (ii) at the Closing, Two Million Dollars ($2,000,000) (the “Balance Sheet Adjustment Amount” ) shall be paid into the Escrow Fund, as defined below, to be held as a reserve for (A) the Closing Date Balance Sheet Reconciliation described in Section 1.6(b)(i) hereof, and (B) the Enrollment Reconciliation described in Section 1.6(b)(ii) hereof.  Upon completion of the Closing Date Balance Sheet Reconciliation and the Enrollment Reconciliation, the funds held in the Escrow Fund shall be paid to the Prospect Parties and/or the Heritage Parties, as appropriate, pursuant to Sections 1.6(b) and 1.6(c), below.

(ii)            Section 1.6(a)(i) through 1.6(a)(iv) are hereby amended and restated as follows:

“(a)          Hard Money Amount .  Concurrently with the execution of this Agreement, the Heritage Parties and the Prospect Parties have executed and delivered: (i) that certain Letter dated as of the date hereof from Greater Midwest to the Prospect Parties (the “ Letter Agreement ”), and (ii) an Escrow Agreement dated as of the date hereof in the form of Exhibit “A” (the “ Escrow Agreement ”) by and among the Heritage Parties, the Prospect Parties and a third party escrow (the “Escrow Agent”).

(i)             The Prospect Parties delivered the various schedules described in Article 2 hereof, other than Schedule 2.28 which is attached hereto, which qualify the representations and warranties given by the Prospect Parties in such Article 2 (with Schedule 2.28, the “ Final Prospect Schedules ”), to the Heritage Parties on May 21, 2008.  The Prospect Parties and the Heritage Parties hereby agree that the third paragraph of Schedule 2.4 is modified to read as follows:

“The real property leases for (i) 1037 E. Palmdale Blvd and (ii) 44469 thru 44471 10 th  Street West, Lancaster, CA 93534 require consent for a change in ownership of Tenant.”

The schedules described in Article 3 hereof, which qualify the representations and warranties given by the Heritage Parties in such Article 3 (the “ Final Heritage Schedules ”) will be prepared and delivered to the Prospect Parties and to the Escrow Agent not later than July 15, 2008.  The Final Prospect Schedules and the Final Heritage Schedules shall constitute the Schedules called for under Article 2 and Article 3, shall qualify the representations and warranties made in such Articles for all purposes of this Agreement and may not, notwithstanding Section 4.8 of this Agreement, thereafter be changed without the consent of the other parties.

(ii)            Pursuant to the Escrow Agreement, the Heritage Parties have deposited the sum of One Million Dollars ($1,000,000) as earnest money (the “Hard Money Amount”) to be held by the Escrow Agent pursuant to the terms and conditions of the Escrow Agreement .

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(iii)           The Heritage Parties have released $500,000 of the Hard Money Amount to the Prospect Parties.  Subject to Section 5.4(d) hereof, such amount shall be non-refundable and shall for all purposes be the property of the Prospect Parties, and shall be credited at Closing to the Purchase Price described in Section 1.6.

(iv)  The Heritage Parties and the Prospect Parties have further agreed that not more than one business day following full execution hereof by the parties hereto, the Heritage Parties shall, by written notice to the Escrow Agent and the Prospect Parties direct that another $500,000 of the Hard Money Amount be released to the Prospect Parties forthwith.  Any amount released to the Prospect Parties under this Section 1.6(a)(iv) shall be credited at Closing to the Purchase Price described in Section 1.6.”

(iii)           Section 1.6(b) is hereby amended and restated as follows:

“(b)          Post Closing Purchase Price Adjustments .

(i)             Balance Sheet Purchase Price Adjustment .  No later than sixty (60) days following the Closing Date, the Heritage Parties shall prepare and deliver to the Prospect Parties at the sole expense of the Heritage Parties the audited consolidated balance sheet of Sierra, Antelope Valley, Pegasus and SMM (collectively referred to herein as the “AV Entities”) as of July 31, 2008 (the “ Closing Date Balance Sheet ”), prepared in accordance with generally accepted accounting principles (“ GAAP ”).  The Prospect Parties will cooperate with such audit, to the extent they have or control the financial records of any of the AV Entities.  Within ten (10) business days of the delivery of the Closing Date Balance Sheet, the Prospect Parties and the Heritage Parties shall effect a reconciliation of the current assets (as defined under GAAP) shown on such Closing Date Balance Sheet ( “Balance Sheet Current Assets Amount” ), on the one hand, and the current liabilities (as defined under GAAP, but including (if not otherwise included under GAAP) accrued payroll and paid time off for employees and Termination Pay for Contracted Employees pursuant to Section 4.7 hereof) and long term debt (if any) on such Closing Date Balance Sheet ( “Balance Sheet Liabilities” ), on the other hand, after elimination of all inter-company accounts between and among the AV Entities and any other entities controlled or affiliated with the Prospect Parties (the “Closing Date Balance Sheet Reconciliation” ).  If the Balance Sheet Liabilities are greater than the Balance Sheet Current Assets Amount, then the Purchase Price shall be reduced by the full amount of the difference between the Balance Sheet Liabilities and the Balance Sheet Current Assets Amount ( “Downward Balance Sheet Adjustment” ).  On the other hand, if the Balance Sheet Current Assets Amount is greater than the Balance Sheet Liabilities, then the Purchase Price shall be increased by the full amount of the difference between the Balance Sheet Current Assets Amount and the Balance Sheet Liabilities ( “Upward Balance Sheet Adjustment” ).  The audit hereunder may include a review and validation of the IBNR reserve amount on the Closing Date Balance Sheet, but shall exclude the reconciliation of such IBNR reserve

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against the actual IBNR, which shall be handled in accordance with Section 4.6 hereof.

Notwithstanding the foregoing if, at the Closing, the Prospect Parties fail to deliver certificates evidencing polices of insurance insuring the AV Entities, the Heritage Parties and their affiliates and the Prospect Parties and their affiliates from and against the tail liability under any of the policies of insurance listed on Schedule 2.18 hereof and written on an occurrence basis (“ Tail Coverage ”), until such tail liability shall have expired, the Heritage Parties may treat the cost of such Tail Coverage as a Balance Sheet Liability for all purposes of this Section 1.6(b)(i).

(ii)            Any adjustments under this Section 1.6(b) and under Section 4.6 shall be excluded from the calculation of the Indemnification Floor and the Indemnification Cap, as such terms are defined in Section 6.2 hereof.”

(iii)           Enrollment Purchase Price Adjustment .  No later than sixty (60) days following the Closing Date, the Heritage Parties and the Prospect Parties shall jointly prepare a reconciliation of the actual Qualified Commercial Enrollee enrollment and the Qualified Senior Enrollee enrollment of the AV Entities as of July 31, 2008, based on the enrollment reports and retroactive additions and deletions for such enrollment received from the health plan insurers for whom the AV Entities provide medical services to enrollees (the “ Enrollment Reconciliation ”).   For purposes of such Enrollment Reconciliation, any Qualified Commercial Enrollees or Qualified Senior Enrollees who were with the AV Entities as shown on Schedule 2.28 under the column “May-08,” and who are, as of July 31, 2008, assigned either to physicians who contract for managed care enrollees exclusively with High Desert Medical Group or to California Desert Medical Group, shall be counted as Qualified Commercial Enrollees and/or Qualified Senior Enrollees who are with the AV Entities as of July 31, 2008.

(A)           If such Enrollment Reconciliation shows that there were fewer than 14,865 Qualified Commercial Enrollees (as defined in Section 2.28 below) assigned to the AV Entities, the Prospect Parties shall pay the Heritage Parties $385.48 for each Qualified Commercial Enrollee below 14,122 Qualified Commercial Enrollees.  If such Enrollment Reconciliation shows that there were more than 14,865 Qualified Commercial Enrollees assigned to the AV Entities, the Heritage Parties shall pay the Prospect Parties $385.48 for each Qualified Commercial Enrollee above 15,608 Qualified Commercial Enrollees.

(B)            If such Enrollment Reconciliation shows that there were fewer than 1,048 Qualified Senior Enrollees (as defined in Section 2.28 below) assigned to the AV Entities, the Prospect Parties shall pay the Heritage Parties $1,927.40 for each Qualified Senior Enrollee below 996 Senior Enrollees.  If such Enrollment Reconciliation shows that there were more than 1,048 Qualified Senior Enrollees assigned to the AV Entities,

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the Heritage Parties shall pay the Prospect Parties $1,927.40 for each Qualified Senior Enrollee above 1,100 Qualified Senior Enrollees.

(C)            The payments due under Sections 1.6(b)(ii)(A) and (B) shall be netted, if applicable, and any net amount due shall be paid as provided in Section 1.6(c) below.

(iv)           Section 1.6(c) is hereby amended and restated as follows:

“(c)          Payment of Adjustment Amounts .

(i)             Not more than two (2) business days following completion of each of the Closing Date Balance Sheet Reconciliation and the Enrollment Reconciliation, the Prospect Parties and the Heritage Parties shall give the Escrow Agent notice of the amount of the payment (if any) due from the Heritage Parties to the Prospect Parties or from the Prospect Parties to the Heritage Parties.

(ii)            If the Closing Date Balance Sheet Reconciliation results in a Downward Balance Sheet Adjustment, the Escrow Agent shall promptly pay such Downward Balance Sheet Adjustment to the Heritage Parties as soon as practicable following receipt of notice of the results of the Closing Date Balance Sheet Reconciliation and without regard to whether the Enrollment Reconciliation has been determined.  If the Closing Date Balance Sheet Reconciliation results in an Upward Balance Sheet Adjustment, the Escrow Agent shall continue to hold such amount until resolution of the Enrollment Reconciliation.  Upon resolution of the Enrollment Reconciliation, the Escrow Agent shall pay the net amount due the Heritage Parties as soon as practicable following receipt of notice of the results of the Enrollment Reconciliation and shall pay any balance remaining in the Escrow after payment of all amounts due the Heritage Parties to the Prospect Parties.

(iii)           Notwithstanding anything set forth herein to the contrary, the payments due following the Closing Date Balance Sheet Reconciliation and the Enrollment Reconciliation shall not be limited to the Balance Sheet Adjustment Amount held by the Escrow Agent.  If the aggregate net payment due either the Heritage Parties or the Prospect Parties exceeds the Balance Sheet Adjustment Amount held by the Escrow Agent, the parties owing such excess amount shall pay the other parties any excess amount not more than ten (10) business days after completion of the last to occur of the Closing Date Balance Sheet Reconciliation and the Enrollment Reconciliation.”

(v)            A new Section 1.6(d) is hereby added to the Agreement as follows:

“(d)          Disputes .  If the Heritage Parties and the Prospect Parties are unable to agree on either the final Closing Date Balance Sheet Reconciliation or the Enrollment Reconciliation on or before October 13, 2008, then (A) they shall determine the aggregate amount of the Balance Sheet Adjustment Amount payable to either or both of the Heritage Parties and/or the Prospect Parties that is not in dispute and shall issue

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written instructions to the Escrow Agent to pay such undisputed amount to the Heritage Parties and/or the Prospect Parties, as applicable, on or before October 15, 2008, and (B) by written notice either Party may submit any dispute related to the disputed portion of the Balance Sheet Adjustment Amount for determination by arbitration in Los Angeles, California, including the determination of the scope or applicability of this agreement to arbitrate.  Such arbitration shall be conducted by a single arbitrator, and shall be administered by JAMS pursuant to its Comprehensive Arbitration Rules and Procedures, as those Rules and Procedures are modified by the agreement of the parties in this Section 1.6(d) (as specifically permitted by JAMS Comprehensive Arbitration Rules and Procedures, Rule 2).  The Heritage Parties and the Prospect Parties shall each pay one-half JAMS fees.  Judgment on the Award issued by the arbitrator may be entered in any court having jurisdiction.  If the Parties are unable to agree upon an arbitrator, an arbitrator with experience in accounting matters will be selected pursuant to JAMS Rule 15 (the “ Designated Arbitrator ”).  Within five (5) business days of the selection of the Designated Arbitrator the Designated Arbitrator shall have a scheduling conference, at which time the Designated Arbitrator shall set out a schedule for the conduct of the arbitration, with the hearing to be held within thirty (30) days of the scheduling conference.  The exchange of information required by Rule 17(a) and pre-hearing submissions required by Rule 20(a) shall be completed no less than ten (10) days before the hearing.  Written statements of position may be submitted pursuant to Rule 20(b).  The Designated Arbitrator shall have ten (10) calendar days from the date of the close of the hearing to issue a ruling, in which the Designated Arbitrator shall select either the position of the Heritage Parties or the position of the Prospect Parties as the final determination of each disputed matter.  The Designated Arbitrator shall have no power to alter or compromise the determinations of the Heritage Parties and the Prospect Parties, but must select one or the other as the prevailing position for each disputed matter.  No discovery whatsoever shall be permitted in connection with the arbitration, including document discovery, deposition discovery or interrogatories.”

4.              Due Diligence .  The Prospect Parties shall deliver the materials described on Exhibit A, attached hereto and incorporated herein by this reference (the “Due Diligence Materials”), to the Heritage Parties on or before July 8, 2008.  If the Due Diligence Materials are not delivered to the Heritage Parties in materially complete form on or before July 8, 2008, then not later than July 11, 2008, the Heritage Parties shall provide to the Prospect Parties written notice specifying which Due Diligence Materials have not been so provided by the Prospect Parties, in which case the Prospect Parties shall supply any such omitted Due Diligence Materials to the Heritage Parties not later than July 21, 2008.  If such omitted Due Diligence Materials are not provided to the Heritage Parties by J