Exhibit 2.31
  AMENDMENT
    NO. 4
  Amendment FMCAG FMCH
  W I T N E S S E
    T H
  Bank Credit Agreement Term Loan Credit Agreement Credit
    Agreements
        Amendments
    Applicable to Both Credit Agreements
      Amendment No. 4
  Amendment No. 4 Effective Date
  Euromedic Acquisition




---



##### 



2




---



##### 



Miscellaneous
  Conditions
    Precedent
        Representations
    and Warranties
        Guarantor
    Acknowledgment
 3




---



##### 



Full Force and
    Effect; Affirmation
  Expenses
  Counterparts
  Credit
    Document
  Governing
    Law
  [REMAINDER
    OF PAGE INTENTIONALLY LEFT BLANK]
 4




---



##### 



[Signatures
    on Following Pages]




---



##### 



BORROWERS AND GUARANTORS:

FRESENIUS MEDICAL CARE AG & Co. KGaA, a German
    partnership limited by shares, represented by FRESENIUS
    MEDICAL CARE MANAGEMENT
    AG, a German corporation, its general partner   By:
    /S/ Michael Brosnan  Name:     Michael
    Brosnan
 Title:
    Member of the Management Board  By:
    /S/ Kent Wanzek  Name:     Kent
    Wanzek
 Title:
    Member of the Management Board




---



##### 



BORROWER AND GUARANTOR:

FRESENIUS MEDICAL CARE NORTH AMERICA HOLDINGS LIMITED
    PARTNERSHIP, a Delaware limited partnershipBy:     Fresenius Medical Care US
    Vermögensverwaltungs GmbH and Co. KG, a German partnershipIts General PartnerBy:
    Fresenius Medical Care
    Vermögensverwaltungs GmbH, a
    German limited liability companyIts
    General Partner   By:
    /S/ Josef Dinger  Name:     Josef
    Dinger
 Title:
    Managing Director




---



##### 



BORROWERS AND GUARANTORS:

FRESENIUS MEDICAL CARE HOLDINGS, INC., a New York
    corporation   By:
    /S/ Mark Fawcett  Name:     Mark
    Fawcett
 Title:
    Vice President and Treasurer




---



##### 



NATIONAL MEDICAL CARE, INC.
 BIO-MEDICAL APPLICATIONS OF ALABAMA, INC.
 BIO-MEDICAL APPLICATIONS OF CALIFORNIA, INC.
 BIO-MEDICAL APPLICATIONS OF FLORIDA, INC.
 BIO-MEDICAL APPLICATIONS OF GEORGIA, INC.
 BIO-MEDICAL APPLICATIONS OF ILLINOIS, INC.
 BIO-MEDICAL APPLICATIONS OF INDIANA, INC.
 BIO-MEDICAL APPLICATIONS OF KENTUCKY, INC.
 BIO-MEDICAL APPLICATIONS OF LOUISIANA, LLC
 BIO-MEDICAL APPLICATIONS OF MICHIGAN, INC.
 BIO-MEDICAL APPLICATIONS OF MINNESOTA, INC.
 BIO-MEDICAL APPLICATIONS OF MISSISSIPPI, INC.
 BIO-MEDICAL APPLICATIONS OF NEW HAMPSHIRE, INC.
 BIO-MEDICAL APPLICATIONS OF NEW JERSEY, INC.
 BIO-MEDICAL APPLICATIONS OF NEW MEXICO, INC.
 BIO-MEDICAL APPLICATIONS OF NORTH CAROLINA, INC.
 BIO-MEDICAL APPLICATIONS OF OHIO, INC.
 BIO-MEDICAL APPLICATIONS OF PENNSYLVANIA, INC.
 BIO-MEDICAL APPLICATIONS OF SOUTH CAROLINA, INC.
 BIO-MEDICAL APPLICATIONS OF TENNESSEE, INC.
 BIO-MEDICAL APPLICATIONS OF TEXAS, INC.
 BIO-MEDICAL APPLICATIONS OF WEST VIRGINIA, INC.
 BIO-MEDICAL APPLICATIONS OF VIRGINIA, INC.
 FRESENIUS USA MANUFACTURING, INC.
 FRESENIUS USA MARKETING, INC.
 FRESENIUS USA, INC.
 SAN DIEGO DIALYSIS SERVICES, INC.
 SPECTRA LABORATORIES, INC.
 WSKC DIALYSIS SERVICES, INC.
 EVEREST HEALTHCARE INDIANA, INC., an Indiana corporation
  By:
    /S/ Mark Fawcett  Name:     Mark
    Fawcett
 Title:
    Vice President and Treasurer




---



##### 



GUARANTORS:

BIO-MEDICAL APPLICATIONS OF MARYLAND, INC., a Delaware
    corporationFRESENIUS SECURITIES, INC., a California corporationSRC HOLDING COMPANY, INC.,a Delaware corporation   By:
    /S/ Mark Fawcett  Name:     Mark
    Fawcett
 Title:
    Vice President and Treasurer




---



##### 



GUARANTORS:

BIO-MEDICAL APPLICATIONS MANAGEMENT COMPANY, INC., a
    Delaware corporationNMC A, LLC, a Delaware limited liability companyBIO-MEDICAL APPLICATIONS OF MAINE, INC., a
    Delaware corporationEVEREST HEALTHCARE HOLDINGS, INC, a Delaware corporationFRESENIUS MANAGEMENT SERVICES, INC, a Delaware corporationRENAL CARE GROUP, INC., a Delaware corporationDIALYSIS CENTERS OF AMERICA  ILLINOIS, INC.,
    an Illinois corporationSTAT DIALYSIS CORPORATION,a Delaware corporationRENAL CARE GROUP OF THE MIDWEST, INC., a Kansas
    corporation   By:
    /S/ Mark Fawcett  Name:     Mark
    Fawcett
 Title:
    Vice President and Treasurer  NEW YORK DIALYSIS SERVICES,
    INC., a New York
    corporation
  By:
    /S/ Mark Fawcett  Name:     Mark
    Fawcett
 Title:
    Treasurer




---



##### 



GUARANTORS:

NATIONAL MEDICAL CARE OF SPAIN, S.A., a corporation
    (sociedad anónima) organized under the laws of Spain   By:
    /S/ Dr. Andrea Stopper  Name:     Dr. Andrea
    Stopper
 Title:
    Authorized Representative




---



##### 



GUARANTORS:

FMC TRUST FINANCE S.à r.l. LUXEMBOURG-III, a private
    limited company (société à responsabilité
    limitée) organized under the laws of Luxembourg   By:
    /S/ Gabriele Dux  Name:     Gabriele
    Dux
 Title:
    Manager  FMC FINANCE III
    S.A., a company
    existing under the laws of Luxembourg
  By:
    /S/ Gabriele Dux  Name:     Gabriele
    Dux
 Title:
    Director  FMC FINANCE VI
    S.A., a
    société anonyme (Public limited company) existing
    under the laws of Luxembourg
  By:
    /S/ Gabriele Dux  Name:     Gabriele
    Dux
 Title:
    Director  FMC FINANCE II S.à
    r.l., a private limited
    company (société à responsabilité
    limitée) organized under the laws of Luxembourg
  By:
    /S/ Gabriele Dux  Name:     Gabriele
    Dux
 Title:
    Director  FMC FINANCE VII
    S.A., a
    société anonyme (Public limited company) existing
    under the laws of Luxembourg
  By:
    /S/ Gabriele Dux  Name:     Gabriele
    Dux
 Title:
    Director




---



##### 



GUARANTORS:

FRESENIUS MEDICAL CARE DEUTSCHLAND GmbH, a German limited
    liability company   By:
    /S/ Alexandra Dambeck  Name:     Alexandra
    Dambeck
 Title:
    Managing Director  By:
    /S/ Eberhard Sieger  Name:     Eberhard
    Sieger
 Title:
    Managing Director  FRESENIUS MEDICAL CARE
    BETEILIGUNGSGESELLSCHAFT
    mbH, a German
    limited liability company
  By:
    /S/ Michael Brosnan  Name:     Michael
    Brosnan
 Title:
    Managing Director  By:
    /S/ Dr. Rainer Runte  Name:     Dr. Rainer
    Runte
 Title:
    Managing Director  FRESENIUS MEDICAL CARE US
    BETEILIGUNGSGESELLSCHAFT
    mbH, a German
    limited liability company
  By:
    /S/ Josef Dinger  Name:     Josef
    Dinger
 Title:
    Managing Director  FRESENIUS MEDICAL CARE
    GmbH, a German
    limited liability company
  By:
    /S/ Gunther Klotz  Name:     Gunther
    Klotz
 Title:
    Managing Director  By:
    /S/ Michael Mareth  Name:     Michael
    Mareth
 Title: Managing Director




---



##### 



GUARANTORS:

FRESENIUS MEDICAL CARE US ZWEI BETEILIGUNGSGESELLSCHAFT
    mbH, a German limited liability company   By:
    /S/ Josef Dinger  Name:     Josef
    Dinger
 Title:
    Managing Director  FRESENIUS MEDICAL CARE US DREI
    BETEILIGUNGSGESELLSCHAFT
    mbH, a German limited
    liability company
  By:
    /S/ Josef Dinger  Name:     Josef
    Dinger
 Title:
    Managing Director  FRESENIUS MEDICAL CARE US ZWEI
    VERMÖGENSVERWALTUNGS GmbH & Co. KG, a German limited
    partnership
  By:
    Fresenius Medical Care
    Vermögensverwaltungs GmbH, a
    German limited liability company  Its General Partner
  By:
    /S/ Josef Dinger  Name:     Josef
    Dinger
 Title:
    Managing Director  FMC FINANCE II S.à
    r.l., a private limited
    company (société à responsabilité
    limitée) organized under the laws of Luxembourg
  By:
    /S/ Gabriele Dux  Name:     Gabriele
    Dux
 Title:
    Manager




---



##### 



ADMINISTRATIVE AGENT
    AND
    COLLATERAL AGENT

BANK OF AMERICA, N.A., for itself in its capacities as
    Administrative Agent and Collateral Agent on behalf of the
    lenders   By:
    /S/ Angela Lau  Name:     Angela
    Lau
 Title:
    Vice President