<PAGE>

                                                                     Exhibit 4.4
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                                                            EXECUTION COPY
                                                            --------------

                        WAIVER OF RIGHTS AND AMENDMENT
                         UNDER STOCKHOLDERS AGREEMENT


     This Waiver of Rights and Amendment under Stockholders Agreement ("Waiver
of Rights") is made and entered into as of December 11, 1996, by and among
Physicians Quality Care, Inc., a Delaware corporation (the "Company"), and each
of the undersigned parties (the "Majority Stockholders").  Capitalized terms not
defined herein shall have the meanings set forth in the Stockholders Agreement
(as hereinafter defined).

     WHEREAS, the Company and the Majority Stockholders, along with certain
other holders of the Company's securities, are parties to a Stockholders
Agreement dated as of August 30, 1996, as amended and in effect from time to
time (the "Stockholders Agreement");

     WHEREAS, the Majority Stockholders collectively hold a majority of all
Shares currently outstanding and subject to the Stockholders Agreement and
collectively hold a majority of the Non-Bain Investor Shares currently
outstanding and subject to the Stockholders Agreement;

     WHEREAS, each of the physicians listed on Exhibit A (the "Non-Retiree
                                               ---------
Flagship Physicians") are becoming parties to the Stockholders Agreement for all
purposes by executing an Instrument of Joinder to Stockholders Agreement dated
as of even date herewith; and

     WHEREAS, pursuant to the provisions of Section 12.2 of the Stockholders
Agreement, the Company and the Majority Stockholders desire to waive certain of
the Company's rights under the Stockholders Agreement as set forth below.

     NOW, THEREFORE, the parties to this Waiver of Rights agree as follows:

1.   As applied to each of the Non-Retiree Flagship Physicians, Section 5.1.1.
     of the Stockholders Agreement is hereby amended to read in its entirety as
     follows:

               5.1.1.   Termination by the Company Without Cause.  If such
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          termination is the result of termination of such holder's employment
          by the Company, its Subsidiaries or any Affiliate thereof without
          Cause or as a result of the death or Disability (as defined in such
          holder's written employment agreement with the Company, its Subsidiary
          or its Affiliate, as applicable (the "Employment Agreement")) of such
          holder, the Company (or its designee), upon written notice delivered
          within 90 days of termination, may purchase all or any portion of the
<PAGE>

          Shares, Warrants and Options then held by the applicable Call
          Stockholder Group at a price equal to the Fair Market Value of such
          securities; provided, however, that upon termination of the employment
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          by the Company, its Subsidiary or any Affiliate thereof of a holder of
          Physician Shares as a result of a Disability of such Physician
          Stockholder, the Company shall have no right to purchase all or any
          portion of the Shares, Warrants and Options then held by the
          applicable Call Stockholder Group for such period of time, if any, as
          such Physician Stockholder is in all respects a Qualified Holder with
          a Total Disability, as hereafter defined.

                    5.1.1.1.  It shall be the responsibility of such Physician
          Stockholder or his/her legal guardian, if any, to notify the Company
          in writing within 30 days of termination of employment as a result of
          Total Disability that such Physician Stockholder should be considered
          a Qualified Holder with a Total Disability and the failure of the
          Physician Stockholder or his/her legal guardian to do so in a timely
          manner shall be determinative of the matter.   Following said notice,
          the Physician Stockholder (in the case of seeking such qualification
          pursuant to Section 5.1.1.3(d)(i), upon the Company's request, or in
          the case of seeking such qualification pursuant to Section
          5.1.1.3(d)(ii), upon the request of the NMA Board (as defined below in
          Section 5.1.1.3(d)(ii)) shall submit to the examination and testing of
          up to three physicians selected by the Company or the NMA Board,
          respectively.  In order for the Physician Stockholder to be medically
          certified as having a Total Disability hereunder pursuant to Section
          5.1.1.3(d)(i), each of the physicians so selected must conclude that
          the Physician Stockholder has a Total Disability in accordance with
          Section 5.1.1.3(d)(i) hereof.  In the case of Physician Stockholders
          who qualify as Totally Disabled hereunder pursuant to Section
          5.1.1.3(d)(i), the Company may require the Physician Stockholder to be
          recertified quarterly thereafter by up to three physicians and the
          Physician Stockholder shall be recertified only by unanimous
          determination of the physicians selected by the Company.  In the case
          of Physician Stockholders who qualify as Totally Disabled hereunder
          pursuant to Section 5.1.1.3(d)(ii), the NMA Board may require the
          Physician Stockholder to be examined by a physician from time to time
          as the NMA Board determines appropriate but in no event more
          frequently than annually.  If the Physician Stockholder shall fail to
          submit to any medical examination or testing requested by the Company
          or the NMA Board hereunder, the Physician Stockholder shall cease to
          be a Qualified Holder with a Total Disability.

                    5.1.1.2.  A Physician Stockholder shall notify the Company
          in writing immediately if the Physician Stockholder ceases, in any
          respect, to be a Qualified Holder with a Total Disability in
<PAGE>

          accordance with Section 5.1.1.3(c) hereof.  Any Physician Stockholder
          who is determined to be a Qualified Holder with a Total Disability
          hereunder shall no longer qualify as such in the event that the
          Physician Stockholder ceases to meet in full all of the criteria set
          forth in Section 5.1.1.3(c) hereof.  The date on which the Company
          determines, and provides notice of such determination to the Physician
          Stockholder, that such Physician Stockholder ceases to be a Qualified
          Holder with a Total Disability shall be the "Disqualification Date".
          In the event a Physician Stockholder ceases to be certified or
          recertified as having a Total Disability or otherwise ceases to be a
          Qualified Holder with a Total Disability, the Physician Stockholder
          shall be treated for purposes of this Agreement as being terminated
          for Cause as of the Disqualification Date.

                    5.1.1.3.  Definitions.  For purposes of this Agreement, the
                              -----------
          following definitions shall apply:

                    (a)  "Basic Activities of Daily Living" shall mean bathing,
          dressing, toileting, continence, eating and the ability to move from a
          sitting to a lying position and vice versa.

                    (b)  "Cognitive Impairment" shall mean confusion or
          disorientation resulting from a deterioration or loss of intellectual
          capacity as a result of Alzheimer's disease, senility or other
          irreversible dementia, which deterioration or loss is capable of being
          diagnosed, and is diagnosed, by standardized testing or instruments.

                    (c)  A "Qualified Holder with a Total Disability" shall mean
          a Physician Stockholder who (i) is Totally Disabled in accordance with
          Section 5.1.1.3 (d) hereof; (ii) is in compliance with and intends to
          remain in compliance with all of his/her obligations under the
          Employment Agreement (including without limitation the restrictive
          covenants), excluding only the Physician Stockholder's obligation to
          provide services thereunder; and (iii) is not working in any capacity,
          with or without compensation, whether as an employee, partner,
          independent contractor or otherwise.

                    (d)  A Physician Stockholder shall be certified as having a
          "Total Disability" by a physician selected by the Company hereunder
          only if (i) the Physician Stockholder (A) is unable to perform three
          or more of the Basic Activities of Daily Living without substantial
          human physical assistance and/or constant supervision or is suffering
          from a Cognitive Impairment and (B) is unable to work in any capacity,
          or (ii) in the event that (after having been examined in accordance
          with the requirements of and followed the procedures set forth in
          Section 5.1.1.1 above) the Physician Stockholder fails to be certified
<PAGE>

          as having a Total Disability pursuant to Section 5.1.1.3(d)(i), (A)
          the Physician Stockholder appeals to the National Medical Advisory
          Board of the Company (the "NMA Board"), and the NMA Board (by vote of
          the majority of all its members) certifies in its sole discretion that
          the Physician Stockholder is permanently disabled and is not able to
          contribute meaningfully as a member of the medical profession, and
          that such determination will not unfairly and adversely affect the
          other physician employees of the Company or its Subsidiaries or
          Affiliates and (B) the NMA Board (by vote of the majority of all its
          members) has not subsequently revoked such certification.

2.   MISCELLANEOUS.

     2.1.  Authority; Effect.  Each party hereto represents and warrants to
           -----------------
          and agrees with each other party that the execution and delivery of
          this Waiver of Rights and the consummation of the transactions
          contemplated hereby have been duly authorized on behalf of such party
          and do not violate any agreement or other instrument applicable to
          such party or by which its assets are bound.  Except to the extent
          specifically amended hereby, the provisions of the Stockholders
          Agreement shall remain unmodified and the provisions of the
          Stockholders Agreement are hereby confirmed as being in full force and
          effect.  This Waiver of Rights does not, and shall not be construed
          to, give rise to the creation of a partnership among any of the
          parties hereto, or to constitute any of such parties members of a
          joint venture or other association.


     2.2.  Notices.  Notices and other communications provided for in this
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          Waiver of Rights shall be given as directed in Section 14.2 of the
          Stockholders Agreement.

     2.3.  Binding Effect, etc.  This Waiver of Rights constitutes the entire
           -------------------
          agreement of the parties with respect to its subject matter,
          supersedes all prior or contemporaneous oral or written agreements or
          discussions with respect to such subject matter, and shall be binding
          upon and inure to the benefit of the parties hereto and their
          respective heirs, representatives, successors and assigns.

     2.4.  Descriptive Headings.  The descriptive headings of this Waiver of
           --------------------
          Rights are for convenience of reference only, are not to be considered
          a part hereof and shall not be construed to define or limit any of the
          terms or provisions hereof.

     2.5.  Counterparts.  This Waiver of Rights may be executed in multiple
           ------------
          counterparts, each of which shall be deemed an original, but all of
          which taken together shall constitute one instrument.
<PAGE>

     2.6.  Severability.  If in any judicial proceedings a court shall refuse
           ------------
          to enforce any provision of this Waiver of Rights, then such
          unenforceable provision shall be deemed eliminated from this Waiver of
          Rights for the purpose of such proceedings to the extent necessary to
          permit the remaining provisions to be enforced.  To the full extent,
          however, that the provisions of any applicable law may be waived, they
          are hereby waived to the end that this Waiver of Rights be deemed to
          be valid and binding agreement enforceable in accordance with its
          terms, and in the event that any provision hereof shall be found to be
          invalid or unenforceable, such provision shall be construed by
          limiting it so as to be valid and enforceable to the maximum extent
          consistent with and possible under applicable law.

     2.7.  Governing Law.  Except to the extent that any provision of this
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          Waiver of Rights is contrary to any mandatory provision of the General
          Corporation Law of the State of Delaware (in which case such mandatory
          statutory provision shall apply), this Waiver of Rights shall be
          governed by and construed in accordance with the domestic substantive
          laws of The Commonwealth of Massachusetts without giving effect to any
          choice or conflict of laws provision or rule that would cause the
          application of the domestic substantive laws of any other
          jurisdiction.



                    [Balance of this page intentionally left blank.]
<PAGE>

     IN WITNESS WHEREOF, each of the undersigned has duly executed this Waiver
of Rights (or caused this Waiver of Rights to be executed on its behalf by its
officer or representative thereunto duly authorized) under seal as of the date
first above written.


THE COMPANY:             PHYSICIANS QUALITY CARE, INC.


                         By:     /s/ Jerilyn P. Asher
                             ---------------------------------------------
                             Name: Jerilyn P. Asher
                             Title: Chief Executive Officer and President


MAJORITY STOCKHOLDERS:   BAIN CAPITAL FUND V, L.P.

                         By Bain Capital Partners V, L.P., a
                               Delaware limited partnership,
                               its general partner

                         By Bain Capital Investors V, Inc., its
                               general partner


                        By /s/
                           --------------------------------------------------
                           Title: Managing Director



                         BAIN CAPITAL FUND V-B, L.P.

                         By Bain Capital Partners V, L.P., a
                               Delaware limited partnership,
                               its general partner

                         By Bain Capital Investors V, Inc., its
                               general partner


                         By  /s/
                         ----------------------------------------------------
                         Title:  Managing Director
<PAGE>

                         BCIP Associates


                         By  /s/
                           --------------------------------------------------
                              Title: a general partner


                         BCIP TRUST ASSOCIATES, L.P.


                         By  /s/
                           -----------------------------------------------
                             Title: a general partner



                            /s/ Jerilyn P. Asher
                          ------------------------------------------------
                         Jerilyn P. Asher, as an individual



                            /s/ Jay Greenberg
                          -----------------------------------------------
                         Jay Greenberg, as an individual



                            /s/ Arlan Fuller, Jr., M.D.
                          ----------------------------------------------
                         Arlan Fuller, Jr., M.D., as an individual



                            /s/ Thomas M. Zizic, M.D.
                          --------------------------------------------
                         Thomas M. Zizic, M.D., as an individual
<PAGE>

Exhibit A -- Non-Retiree Flagship Physicians
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Charles S. Angell, M.D.
John Aucott, M.D.
David C. Barnes, M.D.
Nancy K. Barnett, M.D.
Barbara L. Bean, M.D.
Marshall S. Bedine, M.D.
Richard Berg, M.D.
Peter C. Belitsos, M.D.
Lauren L. Bogue, M.D.
Joyce Burd, M.D.
Nicholas Capozzoli, M.D.
Michael R. Clemmens, M.D.
Enser W. Cole, III, M.D.
Alan M. Davick, M.D.
Timothy F. Doran, M.D.
Barbara A. Duffy, M.D.
Ira Fine, M.D.
Dwight N. Fortier, M.D.
Dana H. Frank, M.D.
Allen M. Friedman, M.D.
Neil Friedman, M.D.
Peter R. Graze, M.D.
Andre Gvozden, M.D.
Faith Hackett, M.D.
Dennis L. Headings, M.D.
Katherine S. Koch, M.D.
S. David Krimins, M.D.
Timothy L. Krohe, M.D.
Alan M. Lake, M.D.
Marshall A. Levine, M.D.
Samuel M. Libber, M.D.
Ann C. Massey, M.D.
Susan M. Molinaro, M.D.
Laura Mumford, M.D.
Mary M. Newman, M.D.
Alan Rosen, M.D.
Saul D. Roskes, M.D.
Michael Rudikoff, M.D.
Peter Schilder, M.D.
Jeffrey Schmidlein, M.D.
Kenneth C. Schuberth, M.D.
Eric J. Seifter, M.D.
Stuart Selonick, M.D.
Stanley P. Watkins, M.D.
Stanley R. Weimer, M.D.
Julia Wen, M.D.
Milan Wister, M.D.
Robert A. Wood, M.D.