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     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 16, 1997
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                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D. C. 20549
 
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                                  FORM 10-K/A
 
                      AMENDMENT TO FORM 10-K ANNUAL REPORT
 
                    Filed pursuant to Section 13 or 15(d) of
 
                      The Securities Exchange Act of 1934
 
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                               MERCK & CO., INC.
 
                                  P.O. BOX 100
 
                   WHITEHOUSE STATION, NEW JERSEY 08889-0100
 
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                                AMENDMENT NO. 1
 
     The undersigned registrant hereby amends the following items, financial
statements, exhibits or other portions of its annual report on Form 10-K for the
fiscal year ended December 31, 1996 as set forth below:
 
1.  Add Exhibit Numbers 99(a), 99(b) and 99(c) as follows:
 


EXHIBIT                                                         METHOD OF
NUMBER                 DESCRIPTION                               FILING
                                              
 
99(a)    -- Financial statements and exhibits       Filed with this Form 10-K/A
            required by Form 11-K Annual Report     Amendment
            pursuant to Section 15(d) of the
            Securities Exchange Act of 1934 for
            the Merck & Co., Inc. Employee
            Savings and Security Plan for the
            fiscal year ended December 31, 1996
 
99(b)    -- Financial statements and exhibits       Filed with this Form 10-K/A
            required by Form 11-K Annual Report     Amendment
            pursuant to Section 15(d) of the
            Securities Exchange Act of 1934 for
            the Merck & Co., Inc. Employee Stock
            Purchase and Savings Plan for the
            fiscal year ended December 31, 1996
 
99(c)    -- Financial statements and exhibits       Filed with this Form 10-K/A
            required by Form 11-K Annual Report     Amendment
            pursuant to Section 15(d) of the
            Securities Exchange Act of 1934 for
            the Hubbard Farms, Inc. Employee
            Savings Plan for the fiscal year
            ended December 31, 1996

 
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                                   SIGNATURES
 
     PURSUANT TO THE REQUIREMENTS OF SECTION 13 OR 15(D) OF THE SECURITIES
EXCHANGE ACT OF 1934, THE REGISTRANT HAS DULY CAUSED THIS AMENDMENT TO BE SIGNED
ON ITS BEHALF BY THE UNDERSIGNED, THEREUNTO DULY AUTHORIZED.
 
                                          MERCK & CO., INC.
Dated:  June 16, 1997
                                               By  RAYMOND V. GILMARTIN
                                              (CHAIRMAN OF THE BOARD,
                                                     PRESIDENT
                                            AND CHIEF EXECUTIVE OFFICER)
 
                                                    By  /s/ CELIA A. COLBERT
                                                            CELIA A. COLBERT
                                                           (ATTORNEY-IN-FACT)
 
     PURSUANT TO THE REQUIREMENTS OF THE SECURITIES EXCHANGE ACT OF 1934, THIS
AMENDMENT HAS BEEN SIGNED BELOW BY THE FOLLOWING PERSONS ON BEHALF OF THE
REGISTRANT AND IN THE CAPACITIES AND ON THE DATES INDICATED.
 


                SIGNATURES                                 TITLE                       DATE
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           RAYMOND V. GILMARTIN              Chairman of the Board,
                                               President and Chief
                                               Executive Officer ;
                                               Principal Executive
                                               Officer ; Director
 
              JUDY C. LEWENT                 Senior Vice President
                                               and Chief Financial
                                               Officer; Principal
                                               Financial Officer
 
             PETER E. NUGENT                 Vice President, Controller ;
                                               Principal Accounting
                                               Officer                                June 16, 1997
         H. BREWSTER ATWATER, JR.
               DEREK BIRKIN
           LAWRENCE A. BOSSIDY
             WILLIAM G. BOWEN
            JOHNNETTA B. COLE
              LLOYD C. ELAM                  Directors 
          CHARLES E. EXLEY, JR.
            WILLIAM N. KELLEY
            EDWARD M. SCOLNICK
             SAMUEL O. THIER

 
     CELIA A. COLBERT, BY SIGNING HER NAME HERETO, DOES HEREBY SIGN THIS
DOCUMENT PURSUANT TO POWERS OF ATTORNEY DULY EXECUTED BY THE PERSONS NAMED,
FILED WITH THE SECURITIES AND EXCHANGE COMMISSION AS AN EXHIBIT TO FORM 10-K, ON
BEHALF OF SUCH PERSONS, ALL IN THE CAPACITIES AND ON THE DATE STATED, SUCH
PERSONS INCLUDING A MAJORITY OF THE DIRECTORS OF THE COMPANY.
 
                                                    By  /s/CELIA A. COLBERT
                                                           CELIA A. COLBERT
                                                          (ATTORNEY-IN-FACT)