<PAGE>

                                                                  Exhibit 10.66




                              AMENDMENT NUMBER 1 TO
                       MEDICAL DIRECTOR SERVICES AGREEMENT

         THIS AMENDMENT NUMBER 1 TO MEDICAL DIRECTOR SERVICES AGREEMENT (this
"Amendment") is made and entered into this 26th day of June, 2002, effective as
of the 1st day of May, 2002, by and between RENAL CARE GROUP ARIZONA, INC., an
Arizona corporation as assignee of Renal Care Group, Inc. (the "Company"), and
ARIZONA NEPHROLOGY ASSOCIATES, PLC, an Arizona professional limited liability
company as assignee of certain individual physicians (the "Group").

                                   WITNESSETH:

         WHEREAS, the Company and the Group are parties to a Medical Director
Services Agreement (Group Practice/Freestanding Facilities), effective as of
September 30, 1996 (the "Agreement"), under which the Group provides medical
director services for dialysis facilities located in Arizona that are owned in
whole or in part by the Company; and

         WHEREAS, Renal Care Group, Inc. assigned the Agreement to the Company;
and

         WHEREAS, individual physician members of the Group assigned the
Agreement to the Group under an Assignment and Assumption Agreement dated June
8, 1999; and

         WHEREAS, the parties to this Amendment now desire to make certain
modifications and amendments to the Agreement as provided in this Amendment; and

         WHEREAS, capitalized terms that are used but not defined in this
Amendment that are defined in the Agreement shall have the meanings set forth in
the Agreement;

         NOW, THEREFORE, in consideration of the mutual promises, covenants and
undertakings set forth in this Amendment and in the Agreement, and other good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties to this Amendment hereby agree as follows:

         1. Definitions. The parties agree that the Agreement is hereby amended
to delete therefrom the definition of the term "Facilities" in the Preamble to
the Agreement. For purposes of the Agreement and this Amendment, the term
"Facilities" means, collectively, the dialysis facilities listed on attached
EXHIBIT A and EXHIBIT A-1 to this Amendment. For purposes of the Agreement and
this Amendment, the term "DRA Facilities" means the dialysis facilities listed
on attached EXHIBIT A-1 to this Amendment. For purposes of the Agreement and
this Amendment, the term "HCFA" and references to the "Health Care Financing
Administration" are hereby deleted from the Agreement, and the terms "CMS" and
"Centers for Medicare and Medicaid Services" are inserted in lieu thereof.

         2. Deletion of DRA Facilities. (a) Except as provided herein and in
subsection (b) below, the Company may from and after the date of this Amendment
through May 1, 2003, upon written notice to the Group that the Company has
entered into a Medical Director Services Agreement with Desert Renal Associates,
PLC ("DRA"), delete the DRA Facilities from the definition of Facilities. From
and after the delivery of such notice (the "Deletion Notice"), the Group shall
not be responsible for the performance of medical director services at the DRA
Facilities, and the Company shall not be responsible for paying the portion of
the medical director fee attributable to the DRA Facilities as contemplated by
Section 3.1 of the Agreement, as amended by this Amendment. Until the delivery
of the Deletion Notice, the Group shall continue

<PAGE>

to subcontract with DRA, so that DRA will provide medical director services for
the DRA Facilities on a subcontracted basis. The parties agree that if the
Company delivers the Deletion Notice, then the Company and the Group will not
enter into any agreement under which the Group will provide medical director
services for any of the DRA Facilities until at least one year after RCG
delivers the Deletion Notice. Notwithstanding the foregoing, the Company agrees
that it shall not enter into any separate Medical Director Services Agreements
with DRA until and unless, after good faith negotiations with DRA (as described
further in subparagraph 2(b) herein), the Group is permitted to own membership
interests representing a minimum aggregate ownership interest of 20% in Renal
Dimensions, LLC ("RDI") or the Group and the Company enter into a joint venture
for other dialysis facilities in Arizona.

                  (b) The Company will from time to time engage in good faith
negotiations with DRA for a period of up to one (1) year from the date of this
Amendment to enter into a new Medical Director Services Agreement with DRA AND
to cause DRA either (i) to permit the Company to offer the Group a membership
interest of at least an aggregate of 20% in RDI, a joint venture between the
Company and DRA, or (ii) to permit the Company to enter into a new joint venture
arrangement with the Group to develop new dialysis facilities in and around
Arizona, notwithstanding the first refusal provisions of the Limited Liability
Company Agreement for RDI in favor of DRA. The Company will report to the Group
at least every two (2) months concerning the status of such negotiations with
DRA. The Company will give the Group written notice if, at any time during the
one (1) year period, the Company determines that it can not enter into a new
Medical Director Services Agreement with DRA or if DRA refuses to permit the
Group ownership in RDI or to enter into a joint venture with the Company as
contemplated above (a "Termination Notice"). If (A) the Company delivers the
Termination Notice, or (B) the Company has not entered into a new Medical
Director Services Agreement with DRA on or before May 1, 2003, then the Company
shall cease to have the right to contract separately with DRA for the DRA
Facilities during the term of this Agreement (i.e. the Company agrees that if
negotiations with DRA fail, it will not enter into separate Medical Director
Services Agreements with DRA for any of the Facilities during the term of this
Agreement as it may be extended as provided below), and the Group will no longer
be required to subcontract with DRA to obtain services for the DRA Facilities.
In furtherance of the foregoing, the term of the Agreement shall be tolled
during the negotiation period, such that, if Company is unsuccessful in its
negotiations with DRA, then the term of the Agreement shall continue for a
period of one (1) year after the earlier of the Company's delivery of a
Termination Notice or May 1, 2003, and the parties shall abide by the terms and
conditions of the Agreement and this Amendment during such extended term.

         3. Responsibilities. The parties agree that Section 1.2 of the
Agreement shall be, and is hereby, amended by deleting such Section in its
entirety and inserting in lieu thereof the following:

                  1.2 Responsibilities. Without limiting the generality of this
         Article I, the Group shall provide the medical director services
         described in EXHIBIT B, which may be revised and updated from time to
         time by the Company, provided that any change that is not a CMS or
         other legal requirement must first be approved by the Group if it
         materially increases the medical director duties hereunder. The Group
         will designate a principal contact for coordination of medical director
         services at each Facility. Such principal contact may not be changed
         without the written consent of the Company, which consent will not be
         unreasonably withheld; provided that the Group will not seek to change
         the principal contact for any Facility more often than once a year
         except in the event of the death, disability or retirement of, or other
         exigent circumstances involving the principal contact.



                                       2
<PAGE>


         4. Compensation for Services. The parties agree that Section 3.1 of the
Agreement shall be, and is hereby, amended by deleting such Section in its
entirety and inserting in lieu thereof, the following:

                  3.1 Compensation. (a) In consideration of the services,
         covenants, and agreements agreed to be performed by the Group during
         the Term, the Company shall pay the Group $1,168,000 per year, payable
         in substantially equal monthly installments in arrears. In addition to
         the annual medical director fee described above, the Group shall be
         eligible for an annual bonus of up to 15% of such annual medical
         director fee (exclusive of the $288,000 fee attributable to the DRA
         Facilities) based upon the success of the Facilities (other than the
         DRA Facilities) in meeting performance criteria for the Facilities and
         Group generally prescribed by Renal Care Group, Inc., parent company of
         the Company ("RCG"), for its facilities in the region in which the
         Facilities are located. This bonus will be first payable for the year
         beginning January 1, 2002 and ending December 31, 2002, but the bonus
         will be prorated based on the period of time during such year after
         Amendment Number 1 to this Agreement was in force. Prior to January 1
         of each year from and including 2002, the Group will give the Company a
         notice stating the allocation of the potential bonus among the
         Facilities (other than the DRA Facilities), showing the percentage of
         the total bonus attributable to each such Facility. Such allocation
         shall be subject to the review and approval of the Company, which
         approval will not be unreasonably withheld. The Group shall make such
         allocation taking into account patient census, patient demographics,
         the amount of time expected to be spent providing medical director
         services to each such Facility and other similar relevant factors. The
         criteria for reviewing and determining the bonus amount will be
         substantially similar to those attached as EXHIBIT C to this Agreement.
         RCG may change the bonus criteria annually, and the Company will
         provide the revised criteria to the Group when adopted. RCG will not
         adopt clinical goals in the bonus criteria that supersede or undermine
         the Group's or any of its physicians' best clinical judgment. The Group
         will have the right to review the computation of the bonus and to
         dispute in good faith the Company's calculation of the bonus based on
         objective evidence of the Group's performance in relation to the bonus
         criteria. The Group agrees to accept this payment (as it may be
         adjusted as provided below) by the Company as the total compensation
         for all services, covenants and agreements pursuant to this Agreement.

                  (b) The Group and the Company acknowledge and agree that
         $288,000 of the base medical director fee contemplated above is
         attributable to the DRA Facilities and that after the delivery of the
         Deletion Notice, the base medical director fee will be deemed
         automatically reduced to $880,000.

                  (c) (i) Beginning 90 days prior to May 1, 2003 and May 1 of
         each year thereafter, if either party believes that the fair market
         value of the services provided by the Group under this Agreement has
         changed in any material way since the most recent anniversary of the
         effective date of a change in compensation payable under this Agreement
         (a "Compensation Adjustment Date"), then such party may notify the
         other that it believes such a change has occurred and the Group and the
         Company shall negotiate in good faith an adjustment to the compensation
         described in Section 3.1(a) above so that it represents fair market
         value for the duties and responsibilities of the Group to be provided
         during the next year under this Agreement. Notwithstanding the



                                       3
<PAGE>

         foregoing, no adjustment pursuant to this subsection (c)(i) to the
         compensation payable under this Agreement shall be effective unless set
         forth in writing signed by the Group's and the Company's authorized
         representatives, which writing shall be deemed an amendment to this
         Agreement.

                           (ii) If the Group and the Company are unable to agree
         on an adjustment, then either may require that an adjustment of the
         compensation hereunder be submitted to a qualified independent third
         party mutually selected by both the Group and the Company to determine
         the fair market value of the services required hereunder, the costs and
         fees of which shall be borne equally by the Group and the Company. If
         the Group and the Company are unable to agree on the third party, then
         each of the Company and the Group shall at its own cost and expense
         select its own qualified independent third party and the average of
         such two determinations of fair market value shall be the revised
         compensation unless such determinations are more than 10% apart, in
         which case such third parties shall mutually select an additional
         qualified independent third party, the fees and expenses of which shall
         be shared equally, who shall determine the fair market value of the
         services hereunder from between the range of the amounts determined by
         the first two appraisals. The fair market value of the services as
         determined in accordance with the provisions of this subsection (c)(ii)
         shall be the compensation payable under this Agreement effective as of
         the applicable anniversary of the Compensation Adjustment Date, and
         such final determination shall be deemed an amendment to this
         Agreement.

                  (d) Any change to the compensation payable hereunder in
         accordance with subsection (c) of this Section 3.1 shall be effective
         as of the applicable anniversary of the Compensation Adjustment Date
         and shall remain effective, and not subject to adjustment under Section
         3.1(c) or otherwise, for at least 12 months from the effective date of
         such change.

         5. Settlement and Release. The Group and the Company, and each of their
officers, directors, trustees, agents, employees, subsidiaries, affiliates,
assigns, successors or heirs, hereby relinquish and release any and all known or
unknown causes of action, claims, demands, liabilities, losses, expenses or
other damages (including attorney's fees) against the other concerning the
negotiation of an increase in the medical director fee payable under the
Agreement or either the Group's or the Company's good faith, or lack thereof, in
such negotiations. The Group and the Company represent that they have consulted
with counsel of their choosing, or have had the opportunity to consult with
counsel of their choosing, have read this Agreement in its entirety, fully
understand and comprehend this Agreement, and assent to and sign this Agreement
by their own free act. If any provision of this Agreement is held to be illegal,
invalid or unenforceable by any court or tribunal of competent jurisdiction,
then those provisions remaining legal, valid and enforceable shall remain in
full force and effect.

         6. Signing Consideration. In consideration of the Group's execution and
delivery of this Agreement with the attendant agreements provided in Sections 2,
3, 4 and 5 of this Amendment, upon the execution and delivery of this Amendment
by the Group and its physicians, the Company shall pay the Group cash in the
amount of $90,000 by wire transfer to an account designated by the Group.

         7. Exhibits. The parties agree that the Agreement is hereby amended by
attaching EXHIBIT A, EXHIBIT A-1, EXHIBIT B and EXHIBIT C in the forms attached
to this Amendment.



                                       4
<PAGE>

         8. No Further Amendment. Except as expressly modified and amended by
this Amendment, the parties agree that the Agreement shall continue in full
force and effect as provided therein, and the parties reaffirm all of its
provisions.

         9. Miscellaneous. The section and other headings used in this Amendment
are for convenience of reference only and shall not affect the interpretation of
this Agreement in any way. This Amendment may be executed in multiple
counterparts, each of which shall be deemed an original for all purposes and all
of which shall be deemed, collectively, one agreement.

         11. Renal Dimensions, LLC. The Company will, within ten business days
following the Group's request, cause its affiliate to sell to the Group a
membership interest representing 10% of the outstanding membership interests in
RDI. The purchase price for such interests will be the fair market value of such
interests as determined by a final appraisal conducted by American Appraisal
Associates. The Company represents that the current draft of an appraisal of
interests representing 20% of the membership interests in RDI indicates that the
fair market value of 10% of the membership interests would be $220,000. The sale
will be conditioned on (i) the Company's affiliate's representation and warranty
that it owns the interests free and clear of all liens, claims and encumbrances
of any nature other than encumbrances arising under the Limited Liability
Company Agreement for RDI, and (ii) the Group's representations and warranties
that it is acquiring the interests for investment purposes only and not for
resale and that it is an accredited investor for purposes of federal and state
securities laws. Prior to the closing of any sale under this Section 11, the
Group will have the opportunity to ask questions of and receive answers from
management of RDI concerning the operations and financial status of RDI. The
Group's right to purchase a 10% interest in RDI under this Section 11 will
expire on August 30, 2002.

    [the remainder of this page intentionally left blank, signatures follow]





                                       5
<PAGE>


         IN WITNESS WHEREOF, this Amendment is executed effective as of the date
first set forth above.

                                        The Company:

                                        RENAL CARE GROUP ARIZONA, INC.



                                        By: /s/ R. Dirk Allison
                                           ------------------------------------
                                        Title: Vice President
                                              ---------------------------------

                                        The Group

                                        ARIZONA NEPHROLOGY ASSOCIATES, PLC



                                        By: /s/ Douglas Anderson, M.D.
                                           ------------------------------------
                                        Title: President
                                              ---------------------------------



                                       6

<PAGE>


         Each physician executing below acknowledges that he or she has read and
understood the terms of this Amendment and the Agreement amended hereby and
hereby confirms and ratifies the acknowledgement set forth in Section 6.1(j) of
the Agreement and the agreements set forth in Article VII of the Agreement, as
provided therein.

                                         /s/ Douglas Chang, M.D.
                                         ---------------------------------------
                                         Douglas Chang, M.D.


                                         /s/ Ronald Hyde, M.D.
                                         ---------------------------------------
                                         Ronald Hyde, M.D.


                                         /s/ Melissa Go, M.D.
                                         ---------------------------------------
                                         Melissa Go, M.D.


                                         /s/ Kenneth Johnson, M.D.
                                         ---------------------------------------
                                         Kenneth Johnson, M.D.


                                         /s/ Kenneth Boren, M.D.
                                         ---------------------------------------
                                         Kenneth Boren, M.D.


                                         /s/ Manuel Abrante, M.D.
                                         ---------------------------------------
                                         Manuel Abrante, M.D.


                                         /s/ Frederick Osario, M.D.
                                         ---------------------------------------
                                         Frederick Osario, M.D.


                                         /s/ Vijay Kumar, M.D.
                                         ---------------------------------------
                                         Vijay Kumar, M.D.


                                         /s/ Jeffrey Packer
                                         ---------------------------------------
                                         Jeffrey Packer, D.O.



                                         ---------------------------------------
                                         Yogesh Amin, M.D.


                                         /s/ Douglas Anderson, M.D.
                                         ---------------------------------------
                                         Douglas Anderson, M.D.


                                         /s/ Richard Flick, M.D.
                                         ---------------------------------------
                                         Richard Flick, M.D.


                                         /s/ David Naai, M.D.
                                         ---------------------------------------
                                         David Naai, M.D.




                                       7
<PAGE>


         Each physician executing below acknowledges that he or she has read and
understood the terms of this Amendment and the Agreement amended hereby and
hereby confirms and ratifies the acknowledgement set forth in Section 6.1(j) of
the Agreement and the agreements set forth in Article VII of the Agreement, as
provided therein.


                                         /s/ Anup Rai, M.D.
                                         ---------------------------------------
                                           Anup Rai, M.D.

                                         /s/ Georgetta Bidwell, M.D.
                                         ---------------------------------------
                                         Georgetta Bidwell, M.D.


                                         /s/ Berne Yee, M.D.
                                         ---------------------------------------
                                           Berne Yee, M.D.





                                       8
<PAGE>


                                    EXHIBIT A

                                   FACILITIES

Renal Care Group - Glendale
5157 W. Thunderbird, Building 3
Glendale, Arizona 85306

Renal Care Group - Sun City
10050 w. Bell Road, Suites 29-31
Sun City, Arizona 85351

Renal Care Group - Sun City West
13830 W. Camino del Sol, Suite 100
Sun City West, Arizona 85375

Renal Care Group - Home Dialysis of Glendale
5157 W. Thunderbird, Suite 306
Glendale, Arizona 85306

Acute Dialysis Services (West Valley)

Renal Care Group - Prescott
1365 Iron Springs Road, Suite A7&8
Prescott, Arizona 86301

Renal Care Group - Apache Junction
11518 East Apache Trail, Suite 109
Apache Junction, Arizona 85220

Renal Care Group - Southwest Mesa
2620 W. Broadway, Suites 1-4
Mesa, Arizona 85202

Renal Care Group - Home Dialysis of Mesa
1750 S. Mesa Drive, Suite 100
Mesa, Arizona 85210

Renal Care Group - East Valley
215 South Power Road, Suite 218
Mesa, Arizona 85206

Renal Care Group - Globe
2250 US Highway 60, Suite 0-2
Miami, Arizona 85539



                                       9
<PAGE>


                             EXHIBIT A (CONTINUED)

                                   FACILITIES

Renal Care Group - Safford
1600 20th Avenue, Unit B, Suite 2
Safford, Arizona 85546

Renal Care Group - Cottonwood
203 S. Candy Lane, Suites 11A&B
Cottonwood, Arizona 86326

Renal Care Group - Lake Havasu
1761 McCulloch Blvd., Suite F
Lake Havasu, Arizona 86403

Renal Care Group - Phoenix
1320 North 10th Street, Suite A
Phoenix, Arizona 85006

Renal Care Group - Scottsdale
8435 E. McDowell Road, Suite 100
Scottsdale, Arizona 85257

Renal Care Group - South Phoenix
4621 South Central Avenue
Phoenix, Arizona 85204

Home Hemo
1750 S. Mesa Drive, Suite 100
Mesa, Arizona 85210




                                       10

<PAGE>


                                   EXHIBIT A-1

                                 DRA FACILITIES

Facilities

Renal Care Group - AK-Chin
16536 North Maricopa Road
Maricopa, AZ 85239

Renal Care Group - Casa Grande
695 E. Cottonwood Lane
Casa Grande, AZ 85222

Renal Care Group - Chandler
912 West Chandler Blvd., Building A
Chandler, AZ 85225

Renal Care Group - Mesa
1337 S. Gilbert Road, Suites 101-103
Mesa, AZ 85210

Renal Care Group - Sacaton
Seed Farm & Skill Center Road, Box 207
Sacaton, AZ 85247

Renal Care Group - Payson
112 W. Cedar Lane
Payson, AZ 85541

Renal Care Group - Show Low
1500 S. White Mountain Rd., Suite 204
Show Low, AZ 85901

Renal Care Group - Sun Lakes
9666 E. Riggs Road, Suite 504
Sun Lakes, AZ 85248

Renal Care Group - Tempe
1449 W. Southern Ave.
Tempe, AZ 85282

Renal Care Group - White River
Highway 73, Milepost 342
P.O. Box 1899
White River, AZ 85941

Acute Dialysis (East Valley)




                                       11

<PAGE>


                                    EXHIBIT B

                  MEDICAL DIRECTOR DUTIES AND RESPONSIBILITIES

                                  (Rev. 2/4/99)

         Qualifications: The Group, through the Practice Physicians, shall be
the "Medical Director" contemplated by these duties and responsibilities. The
Medical Director shall be a licensed physician in the State of Arizona, who
meets the criteria of and ESRD "qualified physician director" as well as the
requirements for Professional Staff membership as enumerated in the Professional
Staff Bylaws.

         Duties and Responsibilities: As required by Title 42 of the Code of
Federal Regulations, the Medical Director has responsibility for the quality of
professional care delivered to the patients at the Facilities. The Medical
Director exercises that responsibility through directing the professional
services of the Facilities and conscientiously applying its policies and
procedures. The Medical Director is a member of the governing body of the
Facilities and serves as the official channel of communications between the
Medical Staff and the Executive Board. Specific responsibilities of the Medical
Director include the administrative, medical and technical services outlined
below. The duties and responsibilities of the Medical Director are separate and
distinct from any Practice Physician's role as an attending nephrologist.

         Specific responsibilities of the Medical Director include:

Administrative

         A. The Medical Director will be responsible for the implementation and
maintenance of written policies and guidelines including:

             1.     Patient care delivery policy and procedures manual.
             2.     Communicable disease control within the unit.
             3.     The RCG Professional Staff Bylaws.
             4.     Maintenance of patient medical records.
             5.     Patient and staff education programs.
             6.     Physical environment, fire and safety, and emergency
                    preparedness of the dialysis Facilities.
             7.     Responsibilities and functions of each category of personnel
                    employed by the Facilities.

         B.  The Medical Director will actively participate in Facilities
             Quality Improvement Programs (CQI) and in multi-disciplinary
             quality assurance programs that monitor the performance of
             co-morbid conditions.

         C.  The Medical Director will participate in an active dialogue with
             the RCG Medical Advisory Board (or its representative) in pursuit
             of the common goal of delivering the best patient care practical.
             This participation requires implementation of MAB mandated
             directives and consideration of its recommendations.



                                       12
<PAGE>

         D.  The Medical Director will review on a timely basis the RCG
             Quality Indicator and patient satisfaction data for the Facilities
             with the manager of the Facilities and will consult with
             attending nephrologists regarding achievement of Quality Indicator
             targets.

         E.  The Medical Director will make available an appropriate physician
             to serve as a representative on the governing body of each
             Facilities.

         F.  The Medical Director will assure that the Facilities and all
             attending physicians comply with applicable ESRD network, State,
             Federal and RCG mandates.

         G.  The Medical Director will review incident reports, patient
             complaints and any disciplinary action of medical staff or  patient
             care personnel monthly.

         H.  The Medical Director will serve as Facilities liaison with
             affiliated medical institutions for services such as renal
             transplantation, hospitalizations and emergency medical services.

         I.  The Medical Director will participate in the Facilities survey
             process by groups such as the State Board of Health, HCFA, NCQA and
             JCAHO, and will then communicate to the Governing Body the results
             of such surveys to the Executive Board (and the medical staff).

         J.  The Medical Director will collaborate with the Chief Medical
             Officer and the MAB in obtaining data from regulatory agencies as a
             part of the RCG strategy to work continuously to improve patient
             care.

         K.  The Medical Director will participate in national RCG Medical
             Director educational conferences.

         L.  The Medical Director will collaborate with the laboratory that
             tests the Facilities's samples to implement ESRD Network, State,
             Federal and RCG mandates.

Medical

         A.  The Medical Director will coordinate the renal health care team to
             ensure quality of care, including the establishment and
             implementation of policies regarding patient care. Among these
             quality of care criteria are:

             -     The suitability of patients admitted to the outpatient
                   dialysis Facilities.
             -     The appropriateness of dialysis prescriptions in the
                   Facilities.
             -     Administration of dialysis-related medications.
             -     Administration of recommended vaccines for ESRD patients and
                   staff.
             -     Existing patient care policies and procedures.

         B.  The Medical Director will supervise the development and
             implementation of both short- and long-term patient care plans
             to enable the selection of the most appropriate ESRD modality.



                                       13
<PAGE>

         C.  The Medical Director will supervise the development and
             implementation of written policies outlining patients' options
             for various treatment modalities, including in-center, home and
             peritoneal dialysis.

         D.  When self-dialysis training or home dialysis training is offered,
             the Medical Director will oversee a program that assures that
             patient teaching materials are available for the use of all
             trainees during training and at times other than during the
             dialysis procedure;

         E.  The Medical Director will work to assure that the ESRD patient
             has appropriate consultation with a renal dietician, social
             worker, financial counselor and other individuals, as needed.

         F.  The Medical Director will oversee the appropriate performance of
             the dialysis orders and day-to-day patient care policy by the
             nursing and technical staff.

         G.  The Medical Director will use reasonable efforts to cause attending
             physicians to comply with the Facilities's policies on patient
             care.

         H.  The Medical Director will review patient satisfaction surveys
             and data, clinical outcomes data, and the Medical Director will
             consult with attending physicians and staff as appropriate to
             implement appropriate action to address issues identified and to
             improve patient care at the Facilities.

Technical

         A.  The Medical Director will participate in the selection of
             cost-effective treatment modalities and dialysis supplies to be
             offered by the Facilities and advise attending physicians regarding
             the compatibility of their dialysis prescriptions with the options
             available at the Facilities.

         B.  The Medical Director will approve policies and procedures ensuring
             the adequate training of nurses and technicians in dialysis science
             techniques.

         C.  The Medical Director will provide continuous availability for
             medical and technical questions to the patient care staff,
             including coverage when the Medical Director is not available.

         D.  The Medical Director will supervise the implementation of a
             dialysis water standards policy including monitoring and
             enforcement.

         E.  The Medical Director will supervise the implementation of a policy
             regarding dialyzer reuse including monitoring and enforcement.

         F.  The Medical Director will supervise the implementation of a
             policy on the administration of intradialytic medications.




                                       14

<PAGE>


                                    EXHIBIT C

                                 BONUS CRITERIA

         The annual evaluation of the RCG Facility and its Medical Director is
essential to our mission, which is "to improve the quality of life and to care
for those patients with chronic and acute renal disease." To achieve this
mission, the Facility and its staff must function collaboratively at the highest
possible level, under the leadership of the Medical Director. The Facility /
Medical Director evaluation will be conducted by the office of the Chief Medical
Officer, to whom the Medical Director is primarily responsible. This evaluation
process must be understood by Medical Directors, since it is an important
component of the RCG policy of continuous quality improvement.

         The Interpretive Guidelines for ESRD Facilities states "Treatment is
under the general supervision of a Director who is a physician. The Medical
Director is responsible for planning, organizing, conducting and directing the
professional ESRD services and must devote sufficient time to carrying out these
responsibilities." The Nephrologist has the medical skills and must develop
leadership and collaborative management skills to fulfill this mandate as
Medical Director. Teamwork and collegiality are highly valued as the leader of
the ESRD team.

         The evaluation will be based on a point system, with annual update, as
authorized by the RCG Medical Advisory Board (MAB). The elements to be measured
and their weight are as follows:

         -    50% based on Clinical Indicators of the Facility. The Clinical
              Indicators are measured monthly and reported quarterly; the unit
              of measurement used is based on the one year rolling average.
              Tracking the Clinical Indicators and observing trends provides
              opportunities for quality improvement using the CQI process. The
              market or regional Quality Management Committee is charged with
              reviewing the outcomes and performance of each Facility and
              Professional Staff member and is also available as a resource to
              the Medical Director.

              The point system has been heavily weighted to encourage certain
              outcomes regarding vascular access: reduction of temporary
              catheters and placement of AV fistulas. Vascular access is also
              the area that is most uniquely influenced by the Medical Director
              and requires concerted effort by the Medical director to bring
              about improvement. The literature clearly shows that mortality and
              morbidity are reduced when early permanent access has been placed;
              while mortality within the Facility is clearly the most important
              outcome, the improvement of this outcome can only come about by
              improvement in the processes of care (such as URR, nutrition,
              anemia, etc.) that are known to impact on patient outcomes.



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         -    30% based on Medical Director administrative duties. Section 5 and
              6 of this Handbook describe the administrative duties in greater
              detail. Guidelines have been prepared for the Medical Directors
              of both Hemodialysis and Home Therapy Facilities. At the back of
              each section is a grid, which is designed to assist the medical
              Director and the Facility Manager in the documentation of the
              performance of these duties. On a monthly basis, the required
              tasks should be completed and both the Medical Director and the
              Facility Manager should initial the completion at the bottom of
              the grid. At a minimum, this will document the compliance of the
              Medical Director with regulatory requirements by Medicare.

              The CQI process is a vital part of the quality improvement process
              of the Facility and the Medical Director is expected to
              participate in this process. Three levels of participation are
              provided for but a High level of participation is expected as
              medical Directors become knowledgeable and proficient with the CQI
              process. The Chief Medical Officer (CMO) and his staff are
              available as resources.

         -    20% based on patient satisfaction with the Facility. The Patient
              Satisfaction Survey will be conducted in the spring of each year
              and the results made available to the Facilities and Medical
              Directors. The Medical Director, as the clinical leader, and the
              Facility Manager, are held responsible for the performance of
              the staff of the Facility. Although not directly under the
              control of the Medical Director, he/she is expected to be a
              positive influence on the staff and their performance in the
              Facility.

         Completion of the duties should be documented in some manner, in
addition to a check mark on the grid sheet, further described in Section 5.
Common tools of documentation include minutes from meetings, a personal Medical
Director notebook, or dictated notes kept in the Facility. The Facility Manager
(or an RCG designee) must concur that the line item on the check list was
completed and initial the monthly grid sheet, with the Medical Director. This
indicates that the line item was completed to the satisfaction of both parties.
The grid sheet and related documentation is the property of the Medical
Director; a copy of the grid sheet should be forwarded monthly to the office of
the Associate Medical Officer for monitoring purposes and for use in the annual
Medical Director evaluation. The Medical director will be held accountable for
meeting facility outcome criteria. Failure to improve outcomes, as measured by
the annual Medical Director evaluation, especially when in the 4th Quartile of
performance, will result in a request for a written explanation to the CMO.



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Clinical Performance Measures (50%)

Hemodialysis Medical Director

(evaluation based on annual rolling average of prior year)

         - URR (% of patients with URRs >=70%)             >80% =10 points
           RCG average 72.9%                             75-80% = 8 points
           BEST REGION 80.7%                           70-74.9% = 6 POINTS
                                                       65-69.9% = 4 points
                                                           <65% = 0 points

-          Hematocrit (% of Hcts >=33%)                    >85% =10 points
           RCG average 74.6%                             80-85% = 8 points
           Best Region 78.4%                           75-79.9% = 6 points
                                                       70-74.9% = 4 points
                                                       65-69.9% = 2 points
                                                           <65% = 0 points

-    Hospitalization (91+ days, based on days per patient year at risk)
           RCG average 12.1 days                       <10 days = 8 points
           Best Region 9.4 days                    10-14.9 days = 6 points
                                                     15-20 days = 2 points
                                                       >20 days = 0 points


         - Mortality (91+ days, based on deaths per 100 patient years at risk)
           RCG average 22.1                                 <20 = 8 points
           Best Region 17.5                             20-23.9 = 6 points
                                                        24-29.9 = 4 points
                                                          30-35 = 2 points
                                                            >35 = 0 points

         - Vascular Access:
           - % of temporary catheters                      <10% = 8 points
             RCG average 25.5%                         10-14.9% = 6 points
             Best Region 17.4%                         15-19.9% = 4 points
                                                         20-25% = 2 points
                                                           >25% = 0 points

           - % native AV fistulas                           >43 = 8 points
             RCG average 29.8%                         38-42.9% = 6 points
             Best Region 42.9%                         33-37.9% = 4 points
                                                       28-32.9% = 2 points
                                                           <28% = 0 points



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         - PTFE clotting events/patient year                <0.3 = 10 points
           RCG average 0.8                              0.3-0.59 =  8 points
           Best region 0.4                              0.6-0.99 =  6 points
                                                         1.0-1.2 =  4 points
                                                            >1.2 =  0 points

Peritoneal Dialysis Medical Director

(valuation based on annual rolling average of prior year)

         - KT/V  (>=2.1)
           RCG average 76.8% CAPD
           RCG average 88.1% CCPD                            >78 = 15 points
                                                          63-78% = 12 points
                                                        68-62.9% = 10 points
                                                        63-67.9% =  8 points
                                                        58-62.9% =  5 points

         - Creatinine Clearance (>=60L CAPD or >=60 L CCPD)
           RCG average 81.2% CAPD                            >75 = 15 points
           RCG average 75.2% CCPD                         70-75% = 12 points
           Weighted average 78.2%                       65-69.9% = 10 points
                                                        60-64.9% =  8 points
                                                        55-59.9% =  5 points

         - Hematocrit (% of Hcts >=33%)                     >85% =10 points
           RCG average 74.6%                              80-85% = 8 points
           Best Region 78.4%                            75-79.9% = 6 points
                                                        70-74.9% = 4 points
                                                        65-69.9% = 2 points
                                                            <65% = 0 points

         - Hospitalization (91+ days, based on days per patient year at risk)
           RCG average 12.1 days                        <10 days = 8 points
           Best Region 9.4 days                     10-14.9 days = 6 points
                                                      15-20 days = 2 points
                                                        >20 days = 0 points

         - Mortality (91+ days, based on deaths per 100 patient years at risk)
           RCG average 20.7                                  <20 = 8 points
           Best Region 15.5                              20-24.9 = 6 points
                                                         24-29.9 = 4 points
                                                           30-35 = 2 points
                                                             >35 = 0 points



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      -  Peritonitis (new cases + relapse)
         RCG average 14.9 months between cases
         Best Region 16.9 months between cases

         >25 months between cases                     15 points
         20-25 months between cases                   12 points
         15-19.9 months between cases                  9 points
         10-14.9 months between cases                  6 points
         >10 months between cases                      0 points

Combination Hemodialysis & Peritoneal Medical Director

For those physicians who oversee both modalities, each is evaluated using the
above criteria. The overall Clinical Quality is then a composite of these,
weighted to reflect the numbers of patients in each modality.

MEDICAL DIRECTOR ADMINISTRATIVE TASKS (30%)

The completion of administrative tasks must be documented by the Medical
Director on a monthly basis. It is important that both the Facility Manager and
the Medical Director document completion of the required tasks. Other Medical
Director functions including such things as meeting with surgeons regarding
access, goals, attendance at medical meetings and literature review regarding
ESRD issues, etc, should also be noted in this record as well, since this
contributes to a high quality Facility.

Participation in monthly review:

        -       Review staffing & training issues impacting patient outcomes
                with Manager
        -       Review water quality
        -       Review dialyzer reuse at the Facility
        -       Review monthly lab of patients below quality goals & develop
                plan
        -       Review trend in hospitalizations, infections
        -       Review temporary catheter usage & trend
        -       Review patient incident reports & trends
        -       Monitor staff physician patient rounding process
        -       Adequacy of staff physician medical documentation

Participation in CQI process:

        -       The CQI process should be a routine process in the facility
                striving to improve its outcomes. As physicians learn this
                process, Medical Directors are expected to participate at higher
                levels. In the meantime, Low, Medium and High participation
                levels may be chosen on the Performance grid, depending on the
                physician's comfort with the process.


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Participation in Professional Staff process:

        -       Participate in the Quarterly Quality conference calls, which
                have physician CME available.

Annual checklist:

        -       Review and approve facility Policy and Procedures and make
                necessary modifications; review and approve clinical protocols.
        -       Review patient satisfaction data annually and in concert with
                the Facility Manager make recommendations for improvement.
        -       Participate with the Manager in the Budget process for the
                Facility.
        -       Participate in Facility surveys by regulatory agencies.

Patient Satisfaction Surveys (PSS) (20%)

The Satisfaction Survey will be conducted in the spring of each year and results
forwarded to each Facility for review and discussion regarding potential areas
of improvement.

        CAREGIVER:
              RCG AVERAGE IN-CENTER 3.43
                            PSS >3.5                       = 8 points
                            PSS >=3.25 and <3.5            = 6 points
                            PSS >=3.0 and <3.25            = 4 points
                            PSS >2.5 and <3.0              = 2 points
                            PSS <2.5                       = 0 points

         RCG average Home 3.75
                            PSS >3.5                       = 8 points
                            PSS >=3.25 and <3.5            = 6 points
                            PSS >=3.0 and <3.25            = 4 points
                            PSS >2.5 and <3.0              = 2 points
                            PSS <2.5                       = 0 points

              Physician:
              RCG AVERAGE IN-CENTER 3.27
                            PSS >3.5                       = 8 points
                            PSS >=3.25 and <3.5            = 6 points
                            PSS >=3.0 and <3.25            = 4 points
                            PSS >2.5 and <3.0              = 2 points
                            PSS <2.5                       = 0 points

         RCG average Home 3.67
                            PSS >3.5                       = 8 points
                            PSS >=3.25 and <3.5            = 6 points
                            PSS >=3.0 and <3.25            = 4 points
                            PSS >2.5 and <3.0              = 2 points



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         DIETICIAN:
         RCG average In-Center 3.27
                            PSS >3.5                       = 4 points
                            PSS >=3.25 and <3.5            = 3 points
                            PSS >=3.0 and <3.25            = 2 points
                            PSS >2.5 and <3.0              = 1 points

         RCG average Home 3.67
                            PSS >3.5                       = 4 points
                            PSS >=3.25 and <3.5            = 3 points
                            PSS >=3.0 and <3.25            = 2 points
                            PSS >2.5 and <3.0              = 1 points

         SOCIAL WORKER:
         RCG average In-Center 3.40
                             PSS >3.5                      = 4 points
                             PSS >=3.25 and <3.5           = 3 points
                             PSS >=3.0 and <3.25           = 2 points
                             PSS >2.5 and <3.0             = 1 points

         RCG average Home 3.51
                             PSS >3.5                      = 4 points
                             PSS >=3.25 and <3.5           = 3 points
                             PSS >=3.0 and <3.25           = 2 points
                             PSS >2.5 and <3.0             = 1 points

         FACILITY:
         RCG average: In-Center 3.24
                            PSS >3.5                       = 4 points
                            PSS >=3.25 and <3.5            = 3 points
                            PSS >=3.0 and <3.25            = 2 points
                            PSS >2.5 and <3.0              = 1 points

         RCG average Home 3.58
                            PSS >3.5                       = 4 points
                            PSS >=3.25 and <3.5            = 3 points
                            PSS >=3.0 and <3.25            = 2 points
                            PSS >2.5 and <3.0              = 1 points



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