EXHIBIT 4

                       FIRST AMENDMENT TO CREDIT AGREEMENT

     This First  Amendment to Credit  Agreement (the  "Amendment") is made as of
this 18th day of July, 2000 by and among AMERICAN MEDICAL  SECURITY GROUP,  INC.
(the  "Borrower"),  the Lenders named therein (the  "Lenders")  and LASALLE BANK
NATIONAL ASSOCIATION, as Agent and Swing Line Lender (the "Agent").

                               W I T N E S S E T H

     WHEREAS,  the  Borrower,  the Agent and the  Lenders  are  parties  to that
certain  Credit  Agreement,  dated as of March 24, 2000, as amended from time to
time, (the "Credit Agreement); and

     WHEREAS,  the parties desire to amend the Credit  Agreement,  as more fully
set forth herein.

     NOW, THEREFORE,  in consideration of the mutual agreements herein contained
and other  good and  valuable  consideration,  the  adequacy  of which is hereby
acknowledged, and subject to the terms and conditions hereof, the parties hereto
agree as follows:

     SECTION 1. DEFINITIONS.  Unless otherwise  defined herein,  all capitalized
terms shall have the meaning given to them in the Credit Agreement.

     SECTION 2. AMENDMENTS TO CREDIT AGREEMENT.

          2.1 Section 6.2 USE OF PROCEEDS is hereby  deleted in its entirety and
     amended by inserting the following in its stead:

               "6.2 USE OF PROCEEDS.  AMS will,  and will cause each  Subsidiary
          to, use the proceeds of the Loans to meet general  corporate  needs of
          AMS  and  its  Subsidiaries  and to  repay  in  full  the  outstanding
          Indebtedness of AMS and its Subsidiaries, and each of them, other than
          the  Indebtedness  reflected  in  Section  5.8 (or  Indebtedness  in a
          principal   amount  not  exceeding   $50,000  for  a  single  item  of
          Indebtedness and $100,000 in the aggregate for all such  Indebtedness)
          and approved by Agent.  AMS will not permit any  Subsidiary to use any
          of the  proceeds of the Loans to purchase or carry any "margin  stock"
          (as defined in Regulation  U), nor will AMS use any of the proceeds of
          the  Loans,  or permit  any  Subsidiary  to use any such  proceeds  to
          finance the  Purchase of any Person  which has not been  approved  and
          recommended  by the  Board  of  Directors  (or  functional  equivalent
          thereof) of such Person.  Following the application of the proceeds of
          the Loans with  respect to any  repurchase  by AMS of its  outstanding
          stock as permitted  pursuant to Section  6.10 hereof,  neither AMS nor
          any  Subsidiary  will permit more than 25% of the value (as determined
          by any  reasonable  method) of the assets of AMS and its  Subsidiaries
          which  are  subject  to  any  limitation  on  sale,  pledge  or  other




          restriction  hereunder  taken as a whole to have been, and to continue
          to be, represented by margin stock".

          2.2 Section 6.10 DIVIDENDS is hereby amended by deleting the amount of
     "$7,200,000" in subsection  (ii) thereof and inserting  "$8,200,000" in its
     stead.

     SECTION 3. CONDITIONS  PRECEDENT.  The  effectiveness  of this Amendment is
expressly conditioned upon satisfaction of the following conditions precedent:

          3.1 The Agent  and the  Lenders  shall  have  received  copies of this
     Amendment duly executed by the Borrower.

          3.2  The  Agent  and  the  Lenders  shall  have  received  such  other
     documents, certificates and assurances as they shall reasonably request.

     SECTION 4.  REAFFIRMATION OF THE BORROWER.  The Borrower hereby  represents
and warrants to the Agent and the Lenders that (i) the  warranties  set forth in
Article 5 of the  Credit  Agreement  are true and  correct on and as of the date
hereof,  except to the extent (a) that any such warranties  relate to a specific
date, or (b) changes  thereto are a result of  transactions  for which the Agent
and the Lenders have  granted  their  consent;  (ii) the Borrower is on the date
hereof  in  compliance  with all of the terms  and  provisions  set forth in the
Credit Agreement as hereby amended;  and (iii) upon execution hereof no Event of
Default has occurred and is continuing or has not previously been waived.

     SECTION  5. FULL FORCE AND  EFFECT.  Except as herein  amended,  the Credit
Agreement and all other Loan Documents shall remain in full force and effect.

     SECTION 6.  COUNTERPARTS.  This  Amendment  may be  executed in two or more
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same document.


                            [SIGNATURE PAGE FOLLOWS]

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     IN WITNESS WHEREOF,  the parties hereto have executed this Amendment on the
day and year specified above.

                                 AMERICAN MEDICAL SECURITY GROUP, INC.


                                 By: /S/ GARY D. GUENGERICH
                                     Name:   Gary D. Guengerich
                                     Title:  Executive Vice President and Chief
                                             Financial Officer


                                 LASALLE BANK NATIONAL ASSOCIATION


                                 By: /S/ JANET R. GATES
                                     Name:   Janet R. Gates
                                     Title:  Senior Vice President


                                 FIRST UNION NATIONAL BANK, NATIONAL BANK, NA


                                 By: /S/ THOMAS L. STITCHBERRY
                                     Name:   Thomas L. Stitchberry
                                     Title:  Senior Vice President


                                ASSOCIATED BANK GREEN BAY, NATIONAL ASSOCIATION


                                By: /S/ DENIS F. HOGAN
                                    Name:    Denis F. Hogan
                                    Title:   Vice President


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