EXHIBIT 99.m18


                     AMENDMENT NO. 1 TO MASTER DISTRIBUTION
                    AND INDIVIDUAL SHAREHOLDER SERVICES PLAN
                                       OF
                      AMERICAN CENTURY CALIFORNIA TAX-FREE
                               AND MUNICIPAL FUNDS
                        AMERICAN CENTURY INVESTMENT TRUST
                        AMERICAN CENTURY MUNICIPAL TRUST
                       AMERICAN CENTURY MUTUAL FUNDS, INC.
                    AMERICAN CENTURY WORLD MUTUAL FUNDS, INC.
                    AMERICAN CENTURY CAPITAL PORTFOLIOS, INC.

                                     A CLASS

     THIS  AMENDMENT NO. 1 TO MASTER  DISTRIBUTION  AND  INDIVIDUAL  SHAREHOLDER
SERVICES PLAN is made as of the 27th day of February,  2004 by each of the above
named  corporations  (the "Issuers").  Capitalized  terms not otherwise  defined
herein shall have the meaning  ascribed to them in the Master  Distribution  and
Individual Shareholder Services Plan.

                                    RECITALS

     WHEREAS,  the  Issuers  are parties to a certain  Master  Distribution  and
Individual Shareholder Services Plan dated September 3, 2002 (the "Plan"); and

     WHEREAS,  American  Century  Mutual  Funds,  Inc.  has added a new  series,
Capital Growth Fund (the "Fund"),  for which the Fund's Board has established an
A class of shares; and

     WHEREAS,  American  Century  Municipal  Trust has established an A class of
shares for the Arizona  Municipal Bond Fund and the Florida  Municipal Bond Fund
(the "ACMT Funds"); and

     WHEREAS,  the parties  desire to amend the Plan to adopt the Plan on behalf
of the Fund and ACMT Funds.

     NOW,  THEREFORE,  in consideration of the mutual promises set forth herein,
the parties hereto agree as follows:

     1. American Century Mutual Funds,  Inc. hereby adopts the Plan on behalf of
the Fund, in accordance  with Rule 12b-1 under the 1940 Act and on the terms and
conditions contained in the Plan.


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     2. American Century Municipal Trust hereby adopts the Plan on behalf of the
ACMT Funds,  in  accordance  with Rule 12b-1 under the 1940 Act and on the terms
and conditions contained in the Plan.

     3. Schedule A to the Plan is hereby amended by deleting the text thereof in
its entirety and inserting in lieu therefor the Schedule A attached hereto.

     4. After the date  hereof,  all  references  to the Plan shall be deemed to
mean the Master  Distribution  and  Individual  Shareholder  Services  Plan,  as
amended by this Amendment No. 1.

     5. In the event of a conflict between the terms of this Amendment No. 1 and
the Plan,  it is the  intention of the parties that the terms of this  Amendment
No. 1 shall  control and the Plan shall be  interpreted  on that  basis.  To the
extent the provisions of the Plan have not been amended by this Amendment No. 1,
the parties hereby confirm and ratify the Plan.

     6. This Amendment No. 1 may be executed in two or more  counterparts,  each
of which shall be an original and all of which  together  shall  constitute  one
instrument.

     IN WITNESS  WHEREOF,  the undersigned have executed this Amendment No. 1 as
of the date first above written.

                                    AMERICAN CENTURY CALIFORNIA TAX-FREE
                                       AND MUNICIPAL FUNDS
                                    AMERICAN CENTURY INVESTMENT TRUST
                                    AMERICAN CENTURY MUNICIPAL TRUST
                                    AMERICAN CENTURY MUTUAL FUNDS, INC.
                                    AMERICAN CENTURY WORLD MUTUAL
                                       FUNDS, INC.
                                    AMERICAN CENTURY CAPITAL PORTFOLIOS, INC.


                               BY:  /s/ Charles A. Etherngton
                                    ----------------------------------------
                                    Charles A. Etherington
                                    Vice President of each of the Issuers


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                                   SCHEDULE A

                         Series Offering A Class Shares


Series                                               Date Plan Effective
------                                               -------------------

American Century California Tax-Free And
Municipal Funds
>>       California High-Yield Municipal Fund        September 3, 2002


American Century Investment Trust
>>       Prime Money Market Fund                     September 3, 2002
>>       Diversified Bond Fund                       September 3, 2002
>>       High-Yield Fund                             September 3, 2002

American Century Municipal Trust
>>       High-Yield Municipal Fund                   September 3, 2002
>>       Arizona Municipal Bond Fund                 February 27, 2004
>>       Florida Municipal Bond Fund                 February 27, 2004


American Century Mutual Funds, Inc.
>>       Select Fund                                 September 3, 2002
>>       New Opportunities II Fund                   September 3, 2002
>>       Large Company Growth Fund                   September 3, 2002
>>       Capital Growth Fund                         February 27, 2004



American Century World Mutual Funds, Inc.
>>       International Growth Fund                   September 3, 2002


American Century Capital Portfolios, Inc.
>>       Large Company Value Fund                    September 3, 2002
>>       Value Fund                                  September 3, 2002




By:   /s/ Charles A. Etherington
      -----------------------------------------------
Name:  Charles A. Etherington
Title: Vice President
Date:  February 27, 2004

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