Document:

<PAGE>   1
                                                                   EXHIBIT 10.41

                                      AMGEN
            AMENDMENT #2 DATED MARCH 13, 2000 TO AGREEMENT NO. 980202

Agreement No. 980202, between Amgen Inc. ("Amgen") and Renal Care Group, Inc.,
including any prior amendments thereto, shall be amended and restated in its
entirety to read as stated below.

This agreement ("Agreement") between Amgen Inc. ("Amgen") and Renal Care Group,
Inc., including the freestanding dialysis center affiliate(s) listed on Appendix
B, (collectively, "Dialysis Center"), sets forth the terms and conditions for
the purchase of EPOGEN(R) (Epoetin alfa) by Dialysis Center for the exclusive
treatment of dialysis patients.

1.       TERM OF AGREEMENT. The "Term" of this Agreement shall be defined as
         April 1, 2000 ("Commencement Date") through March 31, 2001
         ("Termination Date").

2.       DIALYSIS CENTER AFFILIATES. Dialysis Center must provide Amgen with a
         complete list of its dialysis center affiliates ("Affiliates") on or
         before the date this Agreement is executed by Dialysis Center. Only
         those Affiliates approved by Amgen and referenced in Appendix B will be
         eligible to participate under this Agreement. Modifications to the
         dialysis center Affiliates listed on Appendix B may be made pursuant to
         the request of Dialysis Center's corporate headquarters and are subject
         to approval and acknowledgment by Amgen in writing. Amgen requires no
         less than 30 days notice before the effective date of change for any
         addition or deletion of Affiliates hereunder. Amgen reserves the right
         to accept, reject, or immediately terminate any Affiliates with regard
         to participation in this Agreement if Amgen determines that such
         Affiliate is participating in any other contract or incentive with
         Amgen pertaining to the purchase of Epogen(R) or such Affiliate is not
         classified as a freestanding dialysis center or a home dialysis support
         facility.

3.       OWN USE. Dialysis Center hereby certifies that EPOGEN(R) purchased
         hereunder shall be for Dialysis Center's "own use", for the exclusive
         treatment of dialysis patients.

4.       AUTHORIZED WHOLESALERS. Dialysis Center must provide Amgen with a
         complete list of its current wholesalers, from whom Dialysis Center
         intends to purchase EPOGEN(R), and must provide the list to Amgen on or
         before the date this Agreement is executed by Dialysis Center's
         corporate headquarters. The list must include the name and complete
         address of each designated wholesaler. Wholesalers designated by
         Dialysis Center and approved by Amgen to participate in this program
         will be deemed "Authorized Wholesalers". A current listing of Dialysis
         Center's Authorized Wholesalers is referenced in Appendix B.
         Notification of proposed changes to the list of Authorized Wholesalers
         must be provided to Amgen in writing at least 30 days before the
         effective date of the proposed change. Amgen reserves the right to
         accept, reject, or immediately terminate any wholesaler with regard to
         participation in this Agreement. In the event Amgen terminates any
         Authorized Wholesaler from which Dialysis Center is purchasing
         EPOGEN(R), Amgen will work with Dialysis Center to identify other
         possible Authorized Wholesalers from which Dialysis Center may purchase
         EPOGEN(R), and/or arrange a temporary direct purchase relationship
         between Dialysis Center and Amgen until such time as an alternative
         Authorized Wholesaler can be secured by Dialysis Center. If Dialysis
         Center purchases directly from Amgen as contemplated above, Amgen shall
         be deemed an authorized Wholesaler for purposes of this Agreement.
         Dialysis Center agrees to require all Authorized Wholesalers to submit
         product sales information directly to Amgen and to a third-party sales
         reporting organization designated by Amgen.

<PAGE>   2

5.       QUALIFIED PURCHASES. Only EPOGEN(R) purchased under this Agreement by
         Dialysis Center*.

6.       COMMITMENT TO PURCHASE. Dialysis Center agrees to purchase EPOGEN(R)
         for all of its dialysis use requirements for recombinant human
         erythropoietin. Dialysis Center may purchase another brand of
         recombinant human erythropoietin for its dialysis use requirements only
         for the time, and only to the extent, that Amgen has notified Dialysis
         Center's corporate headquarters in writing that Amgen cannot supply
         EPOGEN(R) within and for the time period reasonably required by
         Dialysis Center.

7.       CONFIDENTIALITY. Both Amgen and Dialysis Center agree that this
         Agreement represents and contains confidential information which shall
         not be disclosed to any third party, or otherwise made public, without
         prior written authorization of the other party, except where such
         disclosure is contemplated hereunder or required by law, and then upon
         notification to the other party.

8.       DISCOUNTS. Dialysis Center may qualify for discounts and incentives in
         accordance with the schedules and terms set forth in Appendix A.
         Discounts in arrears will be paid in the form of a check payable to
         Dialysis Center's corporate headquarters. Discounts in arrears will be
         calculated in accordance with Amgen's discount calculation policies
         based on * using the prevailing * as the calculation price, except as
         otherwise provided hereunder. Upon vesting, Amgen will use its best
         efforts to make such discounts available within 30 days after receipt
         by Amgen of data, in a form acceptable to Amgen, detailing all * during
         the applicable period. Payment amounts, as calculated by Amgen, must
         equal or exceed $100.00 for the applicable period to qualify. Subject
         to the section entitled "Breach of Agreement", in the event that Amgen
         is notified in writing that Dialysis Center, and/or any Affiliates (the
         "Acquiree") is acquired by another entity or a change of control
         otherwise occurs with respect to the Acquiree, any discounts which may
         have been earned hereunder shall be paid in the form of a check payable
         to the Acquiree's corporate headquarters subject to the conditions
         described herein. If any Affiliates are added to or deleted from this
         Agreement during any of the periods used for comparison, for any of the
         discounts paid in arrears contained herein, Amgen reserves the right in
         its sole discretion to appropriately adjust Dialysis Center's discounts
         for the relevant periods, by including or excluding any purchases made
         by those Affiliates during any of those periods.

9.       TREATMENT OF DISCOUNTS. Dialysis Center agrees that it will properly
         disclose and account for any discount or other reduction in price
         earned hereunder, in whatever form, (i.e. pricing, discount, or
         incentive) in a way that complies with all applicable federal, state,
         and local laws and regulations, including without limitation, Section
         1128B(b) of the Social Security Act and its implementing regulations.
         Section 1128B(b) requires that a provider of services will properly
         disclose and appropriately reflect the value of any discount or other
         reduction in price earned in the costs claimed or charges made by the
         provider under a federal health care program, as that term is defined
         in Section 1128B(f). Dialysis Center also agrees that it will (a) claim
         the benefit of such discount received, in whatever form, in the fiscal
         year in which such discount was earned or the year after, (b) fully and
         accurately report the value of such discount in any cost reports filed
         under Title XVIII or Title XIX of the Social Security Act, or a state
         health care program, and (c) provide, upon request by the U.S.
         Department of Health and Human Services or a state agency or any other
         federally funded state health care program, the information furnished
         by Amgen concerning the amount or value of such

--------
     *   Omitted information is the subject of a request for confidential
         treatment pursuant to Rule 24b-2 under the Securities Exchange Act of
         1934 and has been filed separately with the Securities and Exchange
         Commission.

                                      -2-
<PAGE>   3

         discount. Dialysis Center's corporate headquarters agrees that it will
         advise all Affiliates, in writing, of any discount received by Dialysis
         Center's corporate headquarters hereunder with respect to purchases
         made by such Affiliates and that said Affiliates will account for any
         such discount in accordance with the above stated requirements.

10.      DATA COLLECTION. Dialysis Center agrees that all data to be provided to
         Amgen pursuant to this Agreement, shall be in a form that does not
         disclose the identity or name of any patient or other
         patient-identifying information such as address, telephone number, or
         social security number. Dialysis Center acknowledges that the data to
         be supplied to Amgen pursuant to this Agreement shall be used to
         support verification of the discounts and incentives referenced herein,
         as well as for Amgen-sponsored research concerning the role of
         EPOGEN(R) in improving treatment outcomes and quality of life of
         dialysis patients. Dialysis Center shall consistently use a unique
         alpha-numeric code (which shall not be the same as the patient's social
         security number) as a "case identifier" to track the care rendered to
         each individual patient over time, and such case identifier shall be
         included in the data provided to Amgen. The key or list matching
         patient identities to their unique case identifiers shall not be
         provided to Amgen personnel. In furtherance of Amgen research, Dialysis
         Center may agree from time to time to use its key to update the patient
         care data by linking it with information concerning health outcomes,
         quality of life, and other pertinent data that may become available to
         Amgen from other sources. Any such linking of data sources shall not
         provide the identity of any patient to Amgen. Amgen agrees that it will
         maintain data supplied under this agreement in confidence and that it
         will not use such data to identify or contact any patient. No reports
         by Amgen concerning analyses of the data or the results of such
         research shall disclose the identity of any patient.

11.      BREACH OF AGREEMENT. Either party may terminate this Agreement for
         breach upon 30 days advance written notice. In addition, in the event
         that Dialysis Center breaches any provision of this Agreement, Amgen
         shall have no obligation to continue to offer the terms described
         herein or pay any further discounts to Dialysis Center.

12.      GOVERNING LAW. This Agreement shall be governed by the laws of the
         State of California and the parties submit to the jurisdiction of the
         California courts, both state and federal.

13.      WARRANTIES. Each party represents and warrants to the other that this
         Agreement (a) has been duly authorized, executed, and delivered by it,
         (b) constitutes a valid, legal, and binding agreement enforceable
         against it in accordance with the terms contained herein, and (c) does
         not conflict with or violate any of its other contractual obligations,
         expressed or implied, to which it is a party or by which it may be
         bound. The party executing this Agreement on behalf of Dialysis Center
         specifically warrants and represents to Amgen that he is authorized to
         execute this Agreement on behalf of and has the power to bind Dialysis
         Center and the Affiliates to the terms set forth in this Agreement. The
         party executing this Agreement on behalf of Amgen specifically warrants
         and represents to Dialysis Center that he is authorized to execute this
         Agreement on behalf of and has the power to bind Amgen to the terms set
         forth in this Agreement.

14.      NOTICES. Any notice or other communication required or permitted
         hereunder shall be in writing and shall be deemed given or made when
         delivered in person or when sent to the other party by first class
         mail, nationally recognized overnight delivery service, or other means
         of written communication at the respective party's current address or
         at such other address as the party shall have furnished to the other in
         accordance with this provision.

                                      -3-
<PAGE>   4

15.      COMPLIANCE WITH HEALTH CARE PRICING LEGISLATION AND STATUTES.
         Notwithstanding anything contained herein to the contrary, at any time
         following the enactment of any federal, state, or local law or
         regulation that in any manner reforms, modifies, alters, restricts, or
         otherwise adversely affects the pricing of or reimbursement available
         for EPOGEN(R), Amgen may, in its sole discretion, upon 30 days notice
         (a) terminate this Agreement, or (b) exclude any Affiliates from
         participating in this Agreement unless such Affiliate(s) certifies in
         writing that they are, or will be, exempt from the provisions
         thereunder. Additionally, in order to assure compliance with any
         existing federal, state or local statute, regulation or ordinance,
         Amgen reserves the right to exclude any Affiliates from the pricing,
         discount, and incentive provisions of this Agreement if, in the opinion
         of Amgen's legal counsel such exclusion is necessary to assure such
         compliance.

16.      FORCE MAJEURE. Neither party will be liable for delays in performance
         or nonperformance of this Agreement or any covenant contained herein if
         such delay or nonperformance is a result of Acts of God, civil or
         military authority, civil disobedience, epidemics, war, failure of
         carriers to furnish transportation, strike, lockout or other labor
         disturbances, inability to obtain material or equipment, or any other
         cause of like or different nature beyond the control of such party.

17.      MISCELLANEOUS. No modification of this Agreement will be effective
         unless made in writing and executed by a duly authorized representative
         of each party, except as otherwise provided hereunder. Neither party
         may assign this Agreement to a third party without the prior written
         consent of the other party. This Agreement may be executed in one or
         more counterparts, each of which is deemed to be an original but all of
         which taken together constitutes one and the same agreement.

18.      ENTIRE AGREEMENT. This Agreement constitutes the entire understanding
         between the parties and supersedes all prior written or oral proposals,
         agreements, or commitments pertaining to the subject matter herein.

Please retain one fully executed original for your records and return the other
fully executed original to Amgen.

THE PARTIES EXECUTED THIS AMENDMENT AS OF THE DATES SET FORTH BELOW.

AMGEN INC.                                   RENAL CARE GROUP, INC.

Signature:   /s/Edward Johnson               Signature:   /s/Robert Stillwell
             ---------------------                        ----------------------
Print Name:  Edward Johnson                  Print Name:  Robert Stillwell
             ---------------------                        ----------------------
Print Title:                                 Print Title: Senior Vice President
             ---------------------                        ----------------------
Date:        March 15, 2000                  Date:        March 15, 2000
             ---------------------                        ----------------------

                                      -4-
<PAGE>   5

                APPENDIX A: DISCOUNT PRICING, SCHEDULE, AND TERMS

1.       PRICING. * Contract prices do not include any wholesaler markup,
         discount or rebate, service fees, or other charges or incentives.

<TABLE>
<CAPTION>
     -------------------------------------------------------------------------------------------------------------------
                                                                                                     CONTRACT PRICE
              NDC                                            DESCRIPTION                           EFFECTIVE 4/1/2000
                                                                                                   THROUGH 3/31/2001
                                                                                                       (PER PACK)
     -------------------------------------------------------------------------------------------------------------------
     <S>                       <C>       <C>                                                       <C>
           55513-126-10        S2        2,000 Unit, 1 mL (2,000 Units/mL) single-use vial                *
                                                   10 vials/pack, 10 packs/case
     -------------------------------------------------------------------------------------------------------------------
           55513-267-10        S3        3,000 Unit, 1 mL (3,000 Units/mL) single-use vial                *
                                                   10 vials/pack, 10 packs/case
     -------------------------------------------------------------------------------------------------------------------
           55513-148-10        S4        4,000 Unit, 1 mL (4,000 Units/mL) single-use vial                *
                                                   10 vials/pack, 10 packs/case
     -------------------------------------------------------------------------------------------------------------------
           55513-144-10       S10       10,000 Unit, 1 mL (10,000 Units/mL) single-use vial               *
                                                   10 vials/pack, 10 packs/case
     -------------------------------------------------------------------------------------------------------------------
           55513-823-10       S40       40,000 Unit, 1 mL (40,000 Units/mL) single-use vial               *
                                                    10 vials/pack, 4 packs/case
     -------------------------------------------------------------------------------------------------------------------
           55513-283-10       M10       20,000 Unit, 2 mL (10,000 Units/mL) multi-use vial                *
                                                    10 vials/pack, 4 packs/case
     -------------------------------------------------------------------------------------------------------------------
           55513-478-10       M20       20,000 Unit, 1 mL (20,000 Units/mL) multi-use vial                *
                                                    10 vials/pack, 4 packs/case
     -------------------------------------------------------------------------------------------------------------------
</TABLE>

                  *

2.       OPTIONAL HEMATOCRIT INCENTIVE. Dialysis Center may qualify for an
         Optional Hematocrit/Hemoglobin Incentive ("OHI") provided the following
         requirements are met:

a.       REQUIREMENTS: Dialysis Center's aggregate * of EPOGEN(R) by all
         Affiliates as listed on Appendix B on the Commencement Date of this
         Agreement must equal or exceed *of the aggregate * of EPOGEN(R) by
         those same Affiliates for the same time period from the previous year.
         In addition, at least * of Dialysis Center's patients must have Average
         Patient Hematocrits (as defined in Section 2(b) below) greater than or
         equal to * during each calendar quarter of the Term. If either of these
         criteria is not met during any given calendar quarter of the Term,
         Dialysis Center will not qualify for the OHI during that quarter.

         In order to participate in the OHI, Dialysis Center must provide the
         following to Amgen or to a data collection vendor specified by Amgen,
         on a monthly basis, and no later than 30 days after the end of each
         month:

----------
     *   Omitted information is the subject of a request for confidential
         treatment pursuant to Rule 24b-2 under the Securities Exchange Act of
         1934 and has been filed separately with the Securities and Exchange
         Commission.

                                      A-1
<PAGE>   6

         i)       all hematocrit test results for each dialysis patient, the
                  date of each test, and a consistent, unique, alpha-numeric
                  identifier (sufficient to consistently track an individual
                  patient without in any way disclosing the identity of the
                  patient), along with the name, address and phone number of the
                  particular Affiliate at which each patient received treatment
                  (collectively the "Data"). Amgen may utilize the Data for any
                  purpose, and reserves the right to audit all Data. Under no
                  circumstances should the Data include any patient identifiable
                  information including, without limitation, name, complete
                  social security number, address or birth date. The identity of
                  the account submitting the Data and any association with the
                  Data will remain confidential. The hematocrit test results
                  mustbe derived from blood samples taken immediately before
                  dialysis treatment using any automated red blood cell counter
                  testing method (e.g. Coulter-counter, Bayer-Technicon, Sysmex,
                  CellDyne), must be reported to the nearest tenth of one
                  percent, and must be submitted directly from the clinical
                  laboratory in a format reasonably acceptable to Amgen. Hand
                  written reports are not acceptable; electronic submission of
                  the Data is preferred, and

         ii)      a properly executed "Annual Certification Letter", a sample of
                  which is attached hereto as Exhibit #1, that will be provided
                  to Dialysis Center's corporate headquarters, unless otherwise
                  requested, after this Agreement is executed by both parties.

b.       CALCULATION: Assuming Dialysis Center has fulfilled all requirements as
         described in Section 2(a) above, Dialysis Center's OHI payment will be
         calculated as follows:

         The "Average Patient Hematocrit" for each dialysis patient will be
         based upon the average of all hematocrit test results gathered for each
         patient during each calendar quarter of the Term. The Average Quarterly
         Percentage of all dialysis patients with Average Patient Hematocrits
         greater than or equal to * will be determined by dividing the total
         number of dialysis patients with Average Patient Hematocrits greater
         than or equal to * by the total number of dialysis patients treated by
         Dialysis Center. The OHI will be calculated based on Dialysis Center's
         overall performance in accordance with Amgen's discount calculation
         policies.

c.       PAYMENT: The OHI will be calculated on a quarterly basis and paid to
         Dialysis Center's corporate headquarters, except as otherwise provided
         hereunder. Payment is contingent upon receipt by Amgen of the "Annual
         Certification Letter" and all required monthly Data for the
         corresponding quarter. If Data is received more than thirty days after
         the last day of any month within a given calendar quarter, the total *
         of EPOGEN(R) attributable to Dialysis Center during such month will be
         excluded from the calculation of the OHI for that quarter.
         Notwithstanding the foregoing, if Amgen receives all required data from
         a minimum of * of all entities within the definition of "Dialysis
         Center" within the time frame referenced above for any month within a
         given calendar quarter, the total * of EPOGEN(R) attributable to
         Dialysis Center during such month, will be included in the calculation
         of the OHI for that quarter. However, if Amgen determines that any
         Affiliate is consistently not submitting the required Data, Amgen
         reserves the right in its sole discretion to exclude such Affiliate's *
         of EPOGEN(R) from the calculation of the OHI for any relevant quarter.
         Quarterly OHI payments will be based upon the Data received from the
         previous quarter, and will equal * during that quarter (exclusive of
         any * of EPOGEN(R) made by Dialysis Center or any Affiliate not meeting
         the Data submission requirements described above) as governed by the

--------
     *   Omitted information is the subject of a request for confidential
         treatment pursuant to Rule 24b-2 under the Securities Exchange Act of
         1934 and has been filed separately with the Securities and Exchange
         Commission.

                                      A-2
<PAGE>   7

         OHI schedule listed below. Notwithstanding the foregoing, payment for
         any period during the Term that is not equivalent to a complete
         calendar quarter, will be based on an average of the Data that is
         available for that period. If the EPOGEN(R) package insert language
         changes, then Amgen and Dialysis Center agree to negotiate in good
         faith a reasonable amendment to the OHI provisions of this Agreement to
         address any such change, if necessary. In addition, at the end of the
         Term of this Agreement, Amgen will conduct an analysis to determine if
         Dialysis Center has achieved the required * growth rate (contemplated
         by Section 2(a) above) throughout the Term of the Agreement. If
         Dialysis Center has achieved the required * growth rate, Amgen will
         reconcile all previous OHI calculations and appropriately adjust the
         OHI for all relevant quarters during the Term in which an OHI was not
         earned.
<TABLE>
<S>                                                                    <C>
   AVERAGE QUARTERLY PERCENTAGE OF ALL DIALYSIS PATIENTS               OPTIONAL HEMATOCRIT
 WITH AVERAGE PATIENT HEMATOCRITS GREATER THAN OR EQUAL TO *           INCENTIVE PERCENTAGE
PLEASE DIRECT YOUR ATTENTION TO THE EPOGEN(R) PACKAGE INSERT
</TABLE>
                                       *

d.       VESTING: Dialysis Center's OHI will vest on the last day of the
         corresponding quarter.

e.       HEMOGLOBIN CONVERSION: Dialysis Center may choose to submit hemoglobin
         test results rather than hematocrit test results as a measurement of
         anemia. If during the Term, Dialysis Center elects to use hemoglobin
         test results, Dialysis Center must: i) submit a "Notification Letter"
         to Amgen, a sample of such Notification Letter is attached hereto as
         Exhibit #2, and ii) begin submitting all hemoglobin test results for
         all dialysis patients along with all other information described in
         Section 2(a) above, rather than hematocrit test results for all
         dialysis patients at each Affiliate for purposes of participating in
         the OHI.

         Amgen will accept the hemoglobin test results, multiply each test
         result by *, and apply the converted results to the same schedule,
         requirements, and calculations described above in place of the
         hematocrit test results.

         For the calendar quarter in which Dialysis Center submits its
         Notification Letter ("Grace Period"), Amgen will apply Dialysis
         Center's Average Quarterly Percentage from the last calendar quarter in
         which complete hematocrit test results were received ("AQP-Hematocrit")
         to the OHI schedule listed above in order to determine the applicable
         OHI Percentage earned by Dialysis Center. If Dialysis Center's overall
         performance on the OHI after the Grace Period does not equal or exceed
         the overall performance by Dialysis Center prior to conversion to
         hemoglobin, Amgen will continue to apply each Affiliate's
         AQP-Hematocrit through the remainder of the Term, provided that during
         the time period the AQP-Hematocrit is applied, *.

         In the event any Affiliates still submitting Data based on hematocrit
         test results are added to this Agreement after Dialysis Center has
         converted to hemoglobin, such Affiliate's * of EPOGEN(R), for the
         calendar quarter in which they were added, shall be included in the
         calculation of the OHI payment. In order for such added Affiliates' *
         of EPOGEN(R) to be included in all subsequent OHI payment calculations,
         such Affiliate must submit hemoglobin test results rather than
         hematocrit.

----------
     *   Omitted information is the subject of a request for confidential
         treatment pursuant to Rule 24b-2 under the Securities Exchange Act of
         1934 and has been filed separately with the Securities and Exchange
         Commission.

                                      A-3
<PAGE>   8
 3.       ELECTRONIC DATA DISCOUNT. Dialysis Center shall be eligible to receive
         a * if certain data elements are transmitted to Amgen electronically.
         The * will be calculated as a percentage of the * of EPOGEN(R)
         attributable to Dialysis Center during each quarter. In order to
         qualify for the *, the following EPOGEN(R) Related Patient Data must be
         submitted by all Affiliates in an electronic format reasonably
         acceptable to Amgen (such as: Excel; Lotus 123.wk1; or text file that
         is tab delimited, comma delimited, or space delimited): Facility ID,
         Patient ID (sufficient to consistently track an individual patient
         without in any way disclosing the identity of the patient), Draw Date,
         Hematocrit, Hemoglobin, Transferrin Saturation, and Ferritin. Such
         EPOGEN(R) Related Patient Data must be submitted, on a monthly basis,
         and no later than 30 days after the end of each month. If such
         EPOGEN(R) Related Patient Data is received more than thirty days after
         the last day of any month within a given calendar quarter, the total *
         of EPOGEN(R) attributable to Dialysis Center during such month will be
         excluded from the calculation of the * for that quarter.
         Notwithstanding the foregoing, if Amgen receives all required data from
         a minimum of * of all entities within the definition of "Dialysis
         Center" within the time frame referenced above for any month within a
         given calendar quarter, the total * of EPOGEN(R) attributable to
         Dialysis Center during such month, will be included in the calculation
         of the * for that quarter. However, if Amgen determines that any
         Affiliate is consistently not submitting the required data, Amgen
         reserves the right in its sole discretion to exclude such Affiliate's *
         of EPOGEN(R) from the calculation of the * for any relevant quarter.
         The Electronic Data Discount will vest on the last day of the
         corresponding quarter, and will be paid 30 days thereafter.

4.       VOLUME PERFORMANCE INCENTIVE. Dialysis Center may qualify for the
         Volume Performance Incentive ("VPI") as described below.

a.       CALCULATION: Dialysis Center's VPI will be calculated in accordance
         with the following formula.

                                       *

         Estimated payments will be made quarterly using Amgen's discount
         calculation policies, and the VPI will be reconciled at the end of the
         Term.

b.       VESTING: Dialysis Center's VPI will vest quarterly.

----------
     *   Omitted information is the subject of a request for confidential
         treatment pursuant to Rule 24b-2 under the Securities Exchange Act of
         1934 and has been filed separately with the Securities and Exchange
         Commission.

                                      A-4
<PAGE>   9

                 APPENDIX B: LIST OF DIALYSIS CENTER AFFILIATES

To ensure you receive the appropriate discount, it is important that we have
your current list of Authorized Wholesalers. The following list represents the
Wholesalers Amgen currently has associated with your contract. Please update the
list by adding or deleting Wholesalers as necessary.

Metro Medical Supply Inc.
3332 Powell Avenue
Nashville, TN  37204

Henry Schein, Inc.
135 Duryea Road
Nelville, NY  11747

Priority HealthCare Corporation
285 West Central Parkway, Suite 1704
Altamonte Springs, FL  32714

                                      B-1
<PAGE>   10

                                                                      EXHIBIT #1

                       SAMPLE ANNUAL CERTIFICATION LETTER

Month X, 199X

FSDC Legal Name
Street Address
City, ST  Zip

RE:  EPOGEN(R) (Epoetin alfa) Agreement No. 9XXXXX

Dear ____________:

Thank you for your participation in the Optional Hematocrit/Hemoglobin Incentive
Program. In order for us to enroll you, we require that a duly authorized
representative of your organization sign the certification below.

Upon receipt of this executed document, we will calculate the value of your
incentive. If we do not receive the executed certification, we cannot provide
you with this incentive.

If you have any questions regarding this letter please contact me at
(805) 447-4134. Thank you for your assistance in returning this certification.

Sincerely,

Sue Simon
Outcomes Incentive Analyst

CERTIFICATION:

On behalf of FSDC Legal Name and all eligible Affiliates participating in the
Optional Hematocrit/Hemoglobin Incentive Program under Agreement No. XXXXXX, the
undersigned hereby certifies that the hematocrit/hemoglobin data and any other
data required to be submitted (herein referred to as "Data"), for each eligible
Affiliate during the term of this Agreement includes the required Data from all
dialysis patients from each such Affiliate, and does not include Data from
non-patients. The party executing this document also represents and warrants
that it (i) has no reason to believe that the submitted Data is incorrect, and
(ii) is authorized to make this certification on behalf of all eligible
Affiliates submitting Data.

FSDC LEGAL NAME

Signature:        _____________________________
Print Name:       _____________________________
Print Title:      _____________________________
Date:             _____________________________

<PAGE>   11

                                                                      EXHIBIT #2

                           SAMPLE NOTIFICATION LETTER

Month X, 199X

Ms. Sue Simon
Outcomes Incentive Analyst
Amgen Inc./Contract Sales Department
One Amgen Center Drive/Mail Stop 37-2-A
Thousand Oaks, CA  91320

RE:  Amgen Agreement No. XXXXXX

Dear Ms. Simon:

This letter serves as notification that FSDC Legal Name and all eligible
Affiliates participating in the Optional Hematocrit/Hemoglobin Incentive Program
under Agreement No. XXXXXX, will begin using hemoglobin test results as a
measurement of anemia as of Month X, 199X, and will begin submitting hemoglobin
test results rather than hematocrit test results for purposes of participating
in the Optional Hematocrit/Hemoglobin Incentive Program.

We understand that any discount under the Optional Hematocrit/Hemoglobin
Incentive Program will now be based solely on hemoglobin test results and that
hematocrit test results will no longer be accepted. We also understand that such
hemoglobin test results will be converted and applied to the same schedule,
requirements, and calculations described in the Optional Hematocrit/Hemoglobin
Incentive Program outlined in the Agreement.

Sincerely,

Name of Administrator
Title<PAGE>   1
                                                                   EXHIBIT 10.55

                             RENAL CARE GROUP, INC.

                      NON-QUALIFIED STOCK OPTION AGREEMENT
                              (FREESTANDING OPTION)

                                 R. DIRK ALLISON

         THIS AGREEMENT is made as of the Date of Grant, by RENAL CARE GROUP,
INC., a corporation organized and existing under the laws of the State of
Delaware (the "Company"), to R. DIRK ALLISON (the "Optionee").

         Upon and subject to the Additional Terms and Conditions attached hereto
and incorporated herein by reference as part of this Agreement, the Company
hereby awards as of the Date of Grant to Optionee an option (the "Option"), as
described below, to purchase the Option Shares.

         A.       DATE OF GRANT:    October 27, 1999.

         B.       TYPE OF OPTION:   Non-Qualified Stock Option.

         C.       EXERCISE PRICE PER SHARE: $16.625.

         D.       OPTION SHARES:    175,000 shares of the Company's Common
                                    Stock, $.01 par value.

         E.       VESTING SCHEDULE:

                  The Vesting Schedule shall be as follows:

                           Schedule         Percentage of Option Shares Vested
                           --------         ----------------------------------

                  Date of Grant                              20%

                  1st anniversary of                         40%
                  the Date of Grant

                  2nd anniversary of                         60%
                  the Date of Grant

                  3rd anniversary of                         80%
                  the Date of Grant

                  4th anniversary of                         100%
                  the Date of Grant

<PAGE>   2

                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

         F.       EXPIRATION DATE: This Option may be exercised at any time
                  after the Date of Grant through 5:00 p.m., Nashville,
                  Tennessee time, on the 10th anniversary of the Date of Grant,
                  provided that this Option may be exercised as to no more than
                  the vested Option Shares, determined pursuant to the Vesting
                  Schedule or as modified as provided herein.

         IN WITNESS WHEREOF, the Company has executed this Agreement the 27th
day of October, 1999.

                                   RENAL CARE GROUP, INC.

                                    By:  /s/ Sam A. Brooks
                                         ---------------------------------------
                                         Sam A. Brooks, President

ATTEST:

/s/ Douglas B. Chappell
---------------------------------
Douglas B. Chappell, Secretary

                                    OPTIONEE:

                                    /s/ R. Dirk Allison
                                    --------------------------------------------
                                    R. DIRK ALLISON

WITNESS:

----------------------------------

                                       2
<PAGE>   3
                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

                         ADDITIONAL TERMS AND CONDITIONS
                             RENAL CARE GROUP, INC.
                      NON-QUALIFIED STOCK OPTION AGREEMENT
                               FOR R. DIRK ALLISON

         1. Exercise of Option. This Option may be exercised in whole or in
part, but in no less than one hundred (100) share lots, by written notice, in
substantially the form as Exhibit 1 hereto, directed to the Secretary of the
Company at its principal place of business, accompanied by payment of the
Exercise Price for the number of shares purchased. Payment shall be made in
cash, by check, or in shares of Common Stock already held by the Optionee prior
to the exercise of the Option. In the event that all or part of the Exercise
Price is paid in shares of Common Stock, the value of such shares shall be equal
to the Fair Market Value of such shares on the date of exercise of the Option,
and the Optionee shall deliver to the Company a certificate or certificates for
such shares.

         2. Issuance of Option Shares. Upon a valid exercise of this Option, the
Company shall, or shall direct its transfer agent to, make delivery of the
Option Shares as soon as reasonably possible; provided, however, that the
Company shall not be required to issue or deliver any certificates for Option
Shares pursuant to this Option prior to (a) the completion of any registration
or qualification of such shares under any federal or state law, or any ruling or
regulation of any governmental body which the Board shall, in its sole
discretion, determine to be necessary or advisable, and/or (b) the Optionee
making at the time of exercise any reasonable representations and warranties
requested by the Company in order to qualify the issuance of the Option Shares
for exemptions from registration under state or federal securities laws. The
Option Shares issued on the exercise of this Option, when paid for as herein
provided, will be fully paid and non-assessable.

         3. Termination of Employment or Death.

            (a) In the event of a termination of Optionee's employment or
consulting services for any reason (other than a termination of an Optionee
employee by his or her death or disability), (i) except as provided in clause
(ii) of this sentence this Option shall terminate as of the day of notice of
such termination by either party, but in no event later than the Expiration
Date, and (ii) any unexercised portion of this Option which is otherwise
exercisable on the date of termination may be exercised by Optionee at any time
within three (3) months following the date of such termination, unless Optionee
dies during such three (3) month period, but in no event later than the
Expiration Date. If Optionee is an employee, whether military, government or
other service by Optionee or other leave of absence granted to Optionee shall
constitute such a termination shall be determined in each case by the Board

                                       3
<PAGE>   4
                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

at its discretion, and any determination by the Board shall be final and
conclusive. If the Board determines that such absence does not constitute such a
termination, however, Optionee may exercise his or her option only with the
consent of the Board.

            (b) If Optionee is an employee, upon termination of Optionee's
employment with the Company (including its subsidiaries) as result of a
permanent disability (as defined by Section 22(e)(3) of the Code), (i) except as
provided in clause (ii) of this sentence, this Option shall terminate and be
unexercisable on the date of such termination, but in no event later than the
Expiration Date, and (ii) any unexercised portion of this Option which is
otherwise exercisable on the date of such termination may be exercised by
Optionee at any time within six (6) months following the date of such
termination, unless Optionee dies during such six (6) month period, but in no
event later than the Expiration Date.

            (c) If Optionee is an employee, upon termination of his or her
employment by the Company without Cause, if there is a written employment
agreement between Optionee and the Company, this Option shall cease to vest in
accordance with the Vesting Schedule regardless of any salary continuation
specified by such employment agreement as a result of such termination. Upon
termination of his or her employment with the Company, (i) except as provided in
clause (ii) of this sentence, this Option shall terminate and be unexercisable
as to unvested options on the date of termination, but in no event later than
the Expiration Date, and (ii) any unexercised portion of this Option which is
otherwise exercisable as of such termination date may be exercised by Optionee
at any time within three (3) months following such termination date, unless
Optionee dies during such three (3) month period such option may be exercised
pursuant to subparagraph (d) below, but in no event later than the Expiration
Date. If there is no written employment agreement between Optionee and the
Company, upon termination of his or her employment by the Company without Cause
any unexercised portion of this Option shall terminate in accordance with
Section 3(a) above, but in no event later than the Expiration Date.

            (d) If Optionee dies, (i) except as provided in clause (ii) of this
sentence, this Option shall terminate and be unexercisable on the date of death,
and (ii) any unexercised portion of this Option, if otherwise exercisable at the
date of death, may be exercised by his or her personal representatives, heirs,
or legatees at any time prior to the expiration of one (1) year after the date
of Optionee's death, but in no event later than the Expiration Date.

         4. Full Information. Optionee represents that he or she is familiar
with the business and affairs of the Company and realizes that the receipt of
the Option and Option Shares is a speculative investment and that any

                                       4
<PAGE>   5
                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

possible profit therefrom is uncertain. Optionee further represents that he or
she has had the opportunity to ask questions of and receive answers from the
Company and any person acting on its behalf and to obtain all information
available with respect to the Company and its affairs, and has received all
information and data with respect to the Company that he or she has requested
and which he or she has deemed relevant in connection with his or her receipt of
the Option and the Option Shares subject to the Option.

         5. No Rights in Option Stock. Optionee shall have no rights as a
stockholder with respect to any of the Option Shares prior to the date of
issuance to the Optionee of a certificate or certificates for such shares.
Optionee shall have no rights with respect to such shares not expressly
conferred by this Agreement.

         6. Stock Reserved. The Company shall at all times during the term of
this Agreement reserve and keep available such number of shares of the Common
Stock as will be sufficient to satisfy the requirements of this Agreement, and
shall pay all original issue taxes on the exercise of this Option, and all other
fees and expenses necessarily incurred by the Company in connection therewith.

         7. Nonassignability. This Option shall not be encumbered or transferred
in whole or in part except by will or the laws of descent and distribution and
is exercisable during the lifetime of the Optionee only by the Optionee.

         8. No Employment. This Agreement shall not give Optionee a right to
employment by, or membership on the board of directors of, the Company or its
subsidiaries.

         9. Non-Qualified Option. It is the intent of the parties hereto that
this Option be a non-qualified stock option and subject to all of the applicable
provisions of the Internal Revenue Code of 1986, as amended. The Company
recognizes that the Optionee may be subject to restrictions regarding his or her
right to trade Common Stock under applicable securities laws. Accordingly, the
Optionee may want to consider making an election to be taxed upon exercise of
this Option under Section 83(b) of the Code. The Optionee shall have sole
discretion to make such an election and shall be solely responsible for
complying with the Code and all relevant rules and regulations in connection
with such election. The Optionee shall provide written notice to the Company of
such election immediately after making such election.

         10. Share Adjustments. If the Company's outstanding shares of Common
Stock are increased or decreased or changed into or exchanged for a different
number or kind of shares or other securities of the Company by

                                       5
<PAGE>   6
                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

reason of any recapitalization, reclassification, stock split, combination of
shares, stock dividend, or transaction having similar effect, the Board shall
proportionately and appropriately adjust the number and kind of shares that are
subject to this Option and the Exercise Price Per Share, without any change in
the aggregate price to be paid therefor upon exercise of this Option.

         11. Changes in Control.

            (a) Change in Control. Subject to Section 12, in the event that a
Change in Control shall occur, then (i) this Option (whether vested or not
vested) shall automatically become one hundred percent (100%) vested
immediately, and (ii) no other terms, conditions, restrictions or limitations
shall be imposed upon this Option after such date, and in no circumstance shall
this Option be forfeited on or after such date.

            (b) Automatic Acceleration and Cash-Out. Subject to Section 12, upon
a Change in Control that results directly or indirectly in the Common Stock (or
the stock of any successor the Company received in exchange for Common Stock)
ceasing to be publicly traded on a national securities market at any time, (i)
this Option shall automatically become one hundred percent (100%) vested
immediately with respect to the Option Shares, (ii) no other terms, conditions,
restrictions or limitations shall be imposed upon this Option after such date,
and in no circumstance shall this Option be forfeited on or after such date, and
(iii) this Option shall be valued and cashed out on the basis of the Change in
Control Price.

            (c) Section 16 Insider. Notwithstanding anything herein to the
contrary, if the Optionee is subject to the reporting requirements of Section 16
of the Exchange Act with respect to the Company, and on the date of the Change
in Control this Option has not been outstanding for a period of at least six
months from the Date of Grant, the Optionee shall not be paid the consideration
described in this Section 11 above until the first day next following the end of
such six-month period.

         12. Modification, Extension and Renewal. The Board may modify, renew or
accept the surrender of this Option, including the acceleration or waiver of any
vesting or other restrictions or limitations, or the conversion of this Option
(with appropriate adjustments) to be applicable to the securities of any
successor corporation to the Company or parent of any such successor, and the
Board may authorize new options in substitution for the Option. Any substituted,
modified or converted options may bear such different or additional terms and
conditions as the Board shall deem appropriate. The determination of the Board
as to the terms of any of the foregoing may be made without regard to whether a
Change in Control has or has not occurred (or whether the Board has determined
that any event shall not be considered

                                       6
<PAGE>   7
                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

to be a Change in Control) and shall be conclusive and binding notwithstanding
the provisions hereof regarding exercisability. Any fractional shares resulting
from any of the foregoing adjustments under this Section shall be disregarded
and eliminated. However, no modification of this Option shall, without the
consent of the Optionee, adversely affect the rights or obligations of the
Optionee with respect to this Option.

         13. Administration. This Agreement shall be administered, construed
and interpreted by the Board.

         14. Definitions.

             "Board" means the Board of Directors of the Company.

             "Change in Control" means a change in control of the Company of a
nature that would be required to be reported (assuming such event has not been
"previously reported") in response to Item 1(a) of a Current Report on Form 8-K
pursuant to Section 13 or 15(d) of the Exchange Act; provided that, without
limitation, a Change in Control shall also be deemed to have occurred at such
time as:

                              (i) any "person" within the meaning of Section
           14(d) of the Exchange Act, other than the Company, a Subsidiary, or
           any employee benefit plan(s) sponsored by the Company or any
           Subsidiary, is or has become the "beneficial owner," as defined in
           Rule l3d-3 under the Exchange Act, directly or indirectly, of 25% or
           more of the combined voting power of the outstanding securities of
           the Company ordinarily having the right to vote at the election of
           directors;

                              (ii) individuals who constitute the Board
           immediately prior to any meeting of stockholders (the "Incumbent
           Board") have ceased for any reason to constitute at least a majority
           thereof after such shareholder meeting, provided that any person
           becoming a director whose election, or nomination for election by the
           Company's stockholders, was approved by a vote of at least
           three-quarters (3/4) of the directors comprising the Incumbent Board
           (either by a specific vote or by approval of the proxy statement of
           the Company in which such person is named as a nominee for director
           without objection to such nomination) shall be, for purposes of this
           Agreement, considered as though such person were a member of the
           Incumbent Board;

                             (iii) upon approval by the Company's stockholders
           of a reorganization, merger, share exchange or consolidation, other
           than one with respect to which those persons who were the beneficial
           owners, immediately prior to such reorganization, merger, share
           exchange or consolidation, of outstanding securities of the Company

                                       7
<PAGE>   8

                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

           ordinarily having the right to vote in the election of directors own,
           immediately after such transaction, more than 75% of the outstanding
           securities of the resulting corporation ordinarily having the right
           to vote in the election of directors; or

                             (iv) upon approval by the Company's stockholders of
           a complete liquidation and dissolution of the Company or the sale or
           other disposition of all or substantially all of the assets of the
           Company other than to a Subsidiary.

            Notwithstanding the occurrence of any of the foregoing, the Board
may determine, if it deems it to be in the best interest of the Company, that an
event or events otherwise constituting a Change in Control shall not be so
considered. Such determination shall be effective if it is made by the Board
prior to the occurrence of an event that otherwise would be or probably will
lead to a Change in Control or after such event if made by the Board a majority
of which is composed of directors who were members of the Board immediately
prior to the event that otherwise would be or probably will lead to a Change in
Control. Upon such determination, such event or events shall not be deemed to be
a Change in Control for any purposes hereunder, including but not limited to,
Section 12.

            "Code" means the Internal Revenue Code of 1986, as amended.

            "Common Stock" means the Common Stock, $.01 par value, of the
Company.

            "Exchange Act" means the Securities Exchange Act of 1934, as
amended, and the rules and regulations thereunder.

            "Fair Market Value" means the closing price of the shares of Common
Stock on a national securities exchange on the day on which such value is to be
determined or, if no shares were traded on such day, on the next preceding day
on which shares were traded, as reported by the National Quotation Bureau, Inc.
or other national quotation service. If the shares are not traded on an exchange
but are traded in the over-the-counter market, on the day on which such value is
to be determined or, if such "asked" price is not available, the last sales
price on such day or, if no shares were traded on such day, on the next
preceding day on which the shares were traded, as reported by the National
Association of Securities Dealers Automatic Quotation System (NASDAQ) or other
national quotation service.

            "Subsidiary" means any corporation that qualifies as a subsidiary of
a corporation under the definition of "subsidiary corporation" contained in
Section 424(f) of the Code.

                                       8
<PAGE>   9

                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

                                    EXHIBIT 1

                              NOTICE OF EXERCISE OF
                            STOCK OPTION TO PURCHASE
                                 COMMON STOCK OF
                             RENAL CARE GROUP, INC.

                                    Name:
                                          --------------------------------

                                    Address:
                                             -----------------------------
                                             -----------------------------

                                    Date:
                                          --------------------------------

  Renal Care Group, Inc.
  Attention:  [Secretary]
  2100 West End, Suite 800
  Nashville, Tennessee  37203

           Re:    Exercise of Non-Qualified Stock Option

  Ladies and Gentlemen:

           Subject to acceptance hereof in writing by Renal Care Group, Inc.
  (the "Company"), I hereby give at least ten days but not more than thirty (30)
  days prior notice of my election to exercise options granted to me to purchase
  _____________ shares of Common Stock of the Company under the Renal Care
  Group, Inc. Non-Qualified Stock Option Agreement granted on
  ______________________, ______. The purchase shall take place as of
  ______________________, ______ (the "Exercise Date").

           On or before the Exercise Date, I will pay the applicable purchase
  price by delivery of a certified check for $__________ for the full purchase
  price payable to the order of Renal Care Group, Inc.

           The required federal, state and local income tax withholding, if any,
  on the exercise of the option shall be paid on or before the Exercise Date.

           I hereby reaffirm that the representations made in Additional Terms
  and Conditions of the Agreement are true and correct as of the date of
  exercising this Option.

                                       9
<PAGE>   10

                                                [OFFICERS/EMPLOYEES/CONSULTANTS]

           As soon as the stock certificate is registered in my name, please
deliver it to me at the above address.

                                                     Very truly yours,

AGREED TO AND ACCEPTED:

RENAL CARE GROUP, INC.

By:
    --------------------------------
Title:
       -----------------------------

Number of Shares Exercised:
                            --------
Number of Shares Remaining:
                            --------

Date:
      ------------------

                                       10

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00006-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00006-of-00352.parquet"}]]