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                                                                   EXHIBIT 10.33



                       THIRD AMENDMENT TO LEASE AGREEMENT


         This Third Amendment to Lease Agreement ("Third Amendment") is entered
into by and between Medical Plaza Partners, Ltd., a Texas limited partnership
("Landlord"), and Billing Information Concepts, Inc., a Delaware corporation
("Tenant").

         For and in consideration of One and No/100 Dollar ($1.00) and other
good and valuable consideration, the receipt and sufficiency of which are
acknowledged, Landlord and Tenant hereby recite and agree as follows:

         1.        Recitals.

                   (a) Lease. Landlord and Tenant entered into the Office
Building Lease Agreement ("Lease") dated July 11, 1996, with respect to certain
Premises situated at 7411 John Smith Drive, San Antonio, Texas, as more
particularly described in the Lease, which Lease was amended by a First
Amendment to Lease Agreement executed effective September 30, 1996, and further
amended by a Second Amendment to Lease Agreement executed effective November 8,
1996.

                  (b) Commencement Date Regarding Floors 2 through 6 of
Building. Pursuant to paragraph II, Phase I, subsection (a), as amended by the
Second Amendment to Lease Agreement, and subsection (b) of the Basic Lease
Information of the Lease, Landlord and Tenant agreed that the Commencement Date
with respect to the 3rd floor would be November 1, 1996, and with respect to the
remaining Phase I floors, 2, 4, 5 and 6, would be the Completion Date as shown
on Exhibit "D" attached to the Lease. Landlord and Tenant have mutually agreed
to establish a revised Commencement Date for Floors 2, 3, 4, 5 and 6 of February
1, 1997, and Landlord and Tenant desire to enter into this Third Amendment to
effect the same.

                   (c) Capitalized Terms. All capitalized terms used herein and
not otherwise specifically defined shall have the same meaning as is ascribed to
such terms in the Lease.

         2.       Agreement of Revised Commencement Date Regarding Floors 2, 3, 
4, 5 and 6 of Building. Landlord and Tenant hereby modify paragraph II, Phase I,
subsection (a), as amended by the Second Amendment to Lease Agreement, and
subsection (b) of the Basic Lease Information to delete any references therein
to a Commencement Date, and agree that the Commencement Date for Floors 2, 3, 4,
5 and 6 shall be February 1, 1997.

         3.       Other Terms. All other terms, conditions and provisions of the
Lease shall remain in full force and effect as of the date thereof.



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         4.       Binding Effect.  This Agreement shall be binding upon and 
shall inure to the benefit of the parties hereto and their respective successors
and assigns.

         5.       Counterparts.  This Agreement may be executed in multiple 
counterparts, each of which shall be an original, but all of which shall
constitute one instrument.

         EXECUTED to be effective on January 24, 1997.

                                         LANDLORD:

                                         MEDICAL PLAZA PARTNERS, LTD.

                                         By:      ORION PARTNERS MEDICAL PLAZA
                                                  LTD., its General Partner

                                                  By:  ORION PARTNERS, INC.,
                                                       its General Partner

                                                       By:   /s/ T.H. Chandler
                                                          ----------------------
                                                       Name:   T.H. Chandler
                                                            --------------------
                                                       Title:   Sr. VP
                                                             -------------------

                                         TENANT:

                                         BILLING INFORMATION CONCEPTS, INC.


                                         By:   /s/ Kelly E. Simmons
                                            ------------------------------------
                                         Name:   Kelly E. Simmons
                                              ----------------------------------
                                         Title:   CFO
                                               ---------------------------------



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