As Filed with the Securities and Exchange Commission on May 14, 2002

                                                     Registration No.: 333-69254

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                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                         POST EFFECTIVE AMENDMENT NO. 1
                                       TO
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           THE SECURITIES ACT OF 1933

                          AMERISOURCEBERGEN CORPORATION
               (Exact Name of Registrant as Specified in Charter)

             DELAWARE                               23-3079390
  (State or Other Jurisdiction of      (I.R.S. Employer Identification Number)
  Incorporation or Organization)

                          1300 Morris Drive, Suite 100
                      Chesterbrook, Pennsylvania 19087-5594
                                 (610) 727-7000
               (Address, including zip code, and telephone number,
        including area code, of Registrant's principal executive offices)

       BERGEN BRUNSWIG CORPORATION 1999 Management Stock Incentive Plan

                            (Full title of the plan)

                           William D. Sprague, Esquire
                          AmerisourceBergen Corporation
                          1300 Morris Drive, Suite 100
                           Chesterbrook, PA 19087-5594
                     (Name and address of agent for service)

                                 (610) 727-7000
          (Telephone number, including area code, of agent for service)



                                EXPLANATORY NOTE

               Upon its effectiveness on September 10, 2001, this Registration
Statement of AmerisourceBergen Corporation (the "Registrant") on Form S-8,
Registration No. 333-69254 (the "Registration Statement"), covered 3,189,559.48
shares of common stock of the Registrant, par value $.01 per share ("Common
Stock"), related to options granted or to be granted under the Bergen Brunswig
Corporation 1999 Management Stock Incentive Plan (the "1999 Management Stock
Plan").

               In connection with the approval and adoption by the Registrant of
an award and incentive compensation plan entitled the AmerisourceBergen
Corporation 2002 Management Stock Incentive Plan (the "2002 Management Stock
Plan"), all shares remaining available for awards under the 1999 Management
Stock Plan are now available for issuance under the 2002 Management Stock Plan.
No further options to purchase shares of Common Stock will hereafter be granted
under the 1999 Management Stock Plan.

               Accordingly, by this Post-Effective Amendment, the Registrant
hereby deregisters 1,771,128 shares of Common Stock covered by the Registration
Statement. These deregistered shares represent all of the shares remaining
available for awards under the 1999 Management Stock Plan as of the effective
date of the 2002 Management Stock Plan registration statement as shares of
Common Stock to be available for offer and sale under the 2002 Management Stock
Plan.

                                      -2-



                                    Signature

               Pursuant to the requirements of the Securities Act of 1933, and
in accordance with Rule 478(a)(4) under the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets the
requirements for filing on Form S-8 and has duly caused this Post-Effective
Amendment to the Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Chesterbrook,
Pennsylvania, on May 14, 2002.

                                     AMERISOURCEBERGEN CORPORATION

                                     By: /s/ R. David Yost
                                         -----------------
                                         R. David Yost, President,
                                         Chief Executive Officer and
                                         Director (Principal Executive Officer)

                                       -3-