**UNITED
      STATES**


**SECURITIES
      AND EXCHANGE COMMISSION**


WASHINGTON,
      D.C. 20549





**FORM
      10-Q/A**





**Amendment
      No. 1**





x
            QUARTERLY
                REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
                ACT OF
                1934
              For
                the quarterly period ended March 31, 2005.o
            TRANSITION
                REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
                ACT OF
                1934
              For
                the transition period from ____________ to
                _____________.








Commission
      File Number: 0-20199








**EXPRESS
      SCRIPTS, INC.**


(Exact
      name of registrant as specified in its charter)








**Delaware**
              (State
                of Incorporation)
            **43-1420563**
              (I.R.S.
                employer identification no.)**13900
                Riverport Dr., Maryland Heights, Missouri**
              (Address
                of principal executive offices)
            **63043**
              (Zip
                Code)





Registrant’s
      telephone number, including area code: (314) 770-1666










Indicate
      by check mark whether the registrant (1) has filed all reports required to
      be
      filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
      the
      preceding 12 months (or for such shorter period that the registrant was required
      to file such reports), and (2) has been subject to such filing requirements
      for
      the past 90 days. Yes 
      x No 
      o





Indicate
      by check mark whether the registrant is an accelerated filer (as defined in
      Rule
      12b-2 of the Exchange Act).  Yes   x  No  o





Common
                stock outstanding as of March 31, 2005:
            74,178,639
            Shares





**Explanatory
      Note**




This
      Amendment No. 1 to Express Scripts, Inc.’s Quarterly Report on Form 10-Q for the
      quarterly period ended March 31, 2005 filed with the Securities and Exchange
      Commission on April 27, 2005 (the “Form 10-Q”) is being filed solely to provide
      corrected certifications pursuant to Exchange Act Rule 13a-14(a) by inserting
      the
      statutory reference to internal control over financial reporting that
      wasinadvertentlyomitted from the introductory sentence of paragraph 4 of
      the certifications previously filed as Exhibits 31.1 and 31.2 to the Form 10-Q.




There
      have been no changes from the original Form 10-Q other than as described above.
      This Amendment No. 1 does not reflect events occurring after the original filing
      of the Form 10-Q, or modify or update in any way disclosures made in the Form
      10-Q.
















**SIGNATURES**




Pursuant
      to the requirements of the Securities Exchange Act of 1934, the registrant
      has
      duly caused this report to be signed on its behalf by the undersigned thereunto
      duly authorized.




EXPRESS
      SCRIPTS, INC.




By:  /s/ George
      Paz


George
      Paz


President
      and Chief Executive Officer





Date:  May
      5,
      2006







**EXHIBIT
      INDEX**




**Exhibit
                Number**
            **Exhibits**31.1
            Certification
                of George Paz, as President and Chief Executive Officer of Express
                Scripts, Inc. pursuant to Exchange Act Rule 13a-14(a).31.2
            Certification
                of Edward Stiften, as Senior Vice President and Chief Financial Officer
                of
                Express Scripts, Inc. pursuant to Exchange Act Rule
                13a-14(a).















I,
      George
      Paz, certify that:




1.
            I
                have reviewed this quarterly report on Form 10-Q of Express Scripts,
                Inc.;




2.
            Based
                on my knowledge, this report does not contain any untrue statement
                of a
                material fact or omit to state a material fact necessary to make
                the
                statements made, in light of the circumstances under which such statements
                were made, not misleading with respect to the period covered by this
                report;




3.
            [Intentionally
                omitted.]




4.
            The
                registrant’s other certifying officers and I are responsible for
                establishing and maintaining disclosure controls and procedures (as
                defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal
                control over financial reporting (as defined in Exchange Act Rules
                13a-15(f) and 15d-15(f)) for the registrant and have:




(a)  designed
      such disclosure controls and procedures, or caused such disclosure controls
      and
      procedures to be designed under our supervision, to ensure that material
      information relating to the registrant, including its consolidated subsidiaries,
      is made known to us by others within those entities, particularly during the
      period in which this report is being prepared;




(b)  designed
      such internal control over financial reporting, or caused such internal control
      over financial reporting to be designed under our supervision, to provide
      reasonable assurance regarding the reliability of financial reporting and the
      preparation of financial statements for external purposes in accordance with
      generally accepted accounting principles;




(c)  evaluated
      the effectiveness of the registrant’s disclosure controls and procedures and
      presented in this report our conclusions about the effectiveness of the
      disclosure controls and procedures, as of the end of the period covered by
      this
      report based on such evaluation; and




(d)  disclosed
      in this report any change in the registrant’s internal control over financial
      reporting that occurred during the registrant’s most recent fiscal quarter (the
      registrant’s fourth fiscal quarter in the case of an annual report) that has
      materially affected, or is reasonably likely to materially affect, the
      registrant’s internal control over financial reporting; and




5.  The
      registrant’s other certifying officers and I have disclosed, based on our most
      recent evaluation of internal control over financial reporting, to the
      registrant’s auditors and the audit committee of the registrant’s board of
      directors (or persons performing the equivalent functions):




(a)  all
      significant deficiencies and material weaknesses in the design or operation
      of
      internal control over financial reporting which are reasonably likely to
      adversely affect the registrant’s ability to record, process, summarize and
      report financial information; and




(b)  any
      fraud, whether or not material, that involves management or other employees
      who
      have a significant role in the registrant’s internal control over financial
      reporting.




Date:
      May
      5, 2006          
      /s/ George
      Paz


G eorge
      Paz, President and


C hief
      Executive Officer
















I,
      Edward
      Stiften, certify that:




1.
            I
                have reviewed this quarterly report on Form 10-Q of Express Scripts,
                Inc.;




2.
            Based
                on my knowledge, this report does not contain any untrue statement
                of a
                material fact or omit to state a material fact necessary to make
                the
                statements made, in light of the circumstances under which such statements
                were made, not misleading with respect to the period covered by this
                report;




3.
            [Intentionally
                omitted.]




4.
            The
                registrant’s other certifying officers and I are responsible for
                establishing and maintaining disclosure controls and procedures (as
                defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal
                control over financial reporting (as defined in Exchange Act Rules
                13a-15(f) and 15d-15(f)) for the registrant and have:




(a)  designed
      such disclosure controls and procedures, or caused such disclosure controls
      and
      procedures to be designed under our supervision, to ensure that material
      information relating to the registrant, including its consolidated subsidiaries,
      is made known to us by others within those entities, particularly during the
      period in which this report is being prepared;




(b)  designed
      such internal control over financial reporting, or caused such internal control
      over financial reporting to be designed under our supervision, to provide
      reasonable assurance regarding the reliability of financial reporting and the
      preparation of financial statements for external purposes in accordance with
      generally accepted accounting principles;




(c)  evaluated
      the effectiveness of the registrant’s disclosure controls and procedures and
      presented in this report our conclusions about the effectiveness of the
      disclosure controls and procedures, as of the end of the period covered by
      this
      report based on such evaluation; and




(d)  disclosed
      in this report any change in the registrant’s internal control over financial
      reporting that occurred during the registrant’s most recent fiscal quarter (the
      registrant’s fourth fiscal quarter in the case of an annual report) that has
      materially affected, or is reasonably likely to materially affect, the
      registrant’s internal control over financial reporting; and




5.  The
      registrant’s other certifying officers and I have disclosed, based on our most
      recent evaluation of internal control over financial reporting, to the
      registrant’s auditors and the audit committee of the registrant’s board of
      directors (or persons performing the equivalent functions):




(a)  all
      significant deficiencies and material weaknesses in the design or operation
      of
      internal control over financial reporting which are reasonably likely to
      adversely affect the registrant’s ability to record, process, summarize and
      report financial information; and




(b)  any
      fraud, whether or not material, that involves management or other employees
      who
      have a significant role in the registrant’s internal control over financial
      reporting.




Date:
      May
      5, 2006          
      /s/ Edward
      Stiften


Edward
      Stiften,
      Senior Vice President and


Chief
      Financial
      Officer