EX-99.906CERT



     CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
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     In connection with the shareholder  report of American  Century  California
Tax-Free and  Municipal  Funds (the  "Registrant")  on Form N-CSR for the period
ending August 31, 2007 (the "Report"), we, the undersigned, certify, pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002, that:

          (1)  The Report fully complies with the  requirements of Section 15(d)
               of the Securities Exchange Act of 1934; and

          (2)  The information  contained in the Report fairly presents,  in all
               material  respects,   the  financial  condition  and  results  of
               operations of the Registrant.


Dated:  October 30, 2007


                                       /s/  Jonathan S. Thomas
                                       ------------------------------------
                                       Jonathan S. Thomas
                                       President
                                       (chief executive officer)




                                      /s/  Robert J. Leach
                                      -------------------------------------
                                      Robert J. Leach
                                      Vice President, Treasurer, and
                                      Chief Financial Officer
                                      (chief financial officer)