<PAGE>   1
                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                                WASHINGTON, D.C.
                                  FORM 10-K/A
                               (AMENDMENT NO. 1)



  [X]         ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                        SECURITIES EXCHANGE ACT OF 1934
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1999
                                       OR
  [ ]       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 1-6446

                              KINDER MORGAN, INC.
                              -------------------
               (Exact name of issuer as specified in its charter)

<TABLE>
<CAPTION>
                          Kansas
                          ------                                                       48-0290000
<S>                                                                     <C>
(State or other jurisdiction of incorporation or organization)          (I.R.S. Employer Identification Number)


         1301 McKinney, Suite 3400, Houston, Texas                                       77010
         -----------------------------------------                                       -----
         (Address of principal executive offices)                                      (Zip Code)

</TABLE>

                                 (713) 844-9500
                                 --------------
              Registrant's telephone number, including area code:

          Securities registered pursuant to Section 12(b) of the Act:

<TABLE>
    <S>                                              <C>
             Title of Each Class                     Name of each exchange on which registered
             -------------------                     -----------------------------------------
    Common Stock, par value $5 per share                      New York Stock Exchange
       Preferred share purchase rights                        New York Stock Exchange

</TABLE>

          Securities registered pursuant to Section 12(g) of the Act:

                 Preferred Stock, Class A $5 cumulative series
                 ---------------------------------------------
                                (Title of class)

         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
                                                     ---       ---

         Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulations S-K is not contained herein, and will not be contained
to the best of the registrant's knowledge, in definitive proxy or information
statements incorporated by referenced in Part III of this Form 10-K or any
amendment to this Form 10-K.[ ].

         The aggregate market value of the voting stock held by nonaffiliates
of the registrant was $2,168,755,111 as of March 10, 2000.

         The number of shares outstanding of each of the registrant's classes
of common stock, as of the latest practicable date was: Common stock, $5 par
value; authorized 150,000,000 shares; outstanding 113,035,166 shares as of
March 10, 2000.

                      Documents Incorporated by Reference
                      -----------------------------------

Part III of this report incorporates by reference specific portions of the
Registrant's Proxy Statement relating to the 2000 Annual Meeting of
Stockholders.




<PAGE>   2



                              KINDER MORGAN, INC.
                                  FORM 10-K/A
                                AMENDMENT NO. 1

         This Report on Form 10-K/A (Amendment No. 1) is filed by Kinder
Morgan, Inc. (the "Registrant") for the purposes of (i) revising certain
sections of Item 14 to the Report on Form 10-K for the year ended December 31,
1999 previously filed by the Registrant, and (ii) filing certain exhibits
including exhibits which were previously incorporated by reference on the Form
10-K.

ITEM 14.     EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K.

Subsections (a)(1) and (a)(2) of Item 14 which were previously filed with the
Form 10-K are hereby incorporated by reference from the Form 10-K without any
changes or amendments.

The section of Item 14 entitled "Executive Compensation Plans and Arrangements"
is hereby amended and supplemented by replacing the current text of that
section in its entirety with the following:

             Executive Compensation Plans and Arrangements

             1987 Directors' Deferred Fee Plan As Amended and Form of
         Participation Agreement regarding the Plan (Exhibit 10(h) to the
         Annual Report on Form 10-K for the year ended December 31, 1995)

             Kinder Morgan, Inc. Amended and Restated 1992 Stock Option Plan
         for Nonemployee Directors (Appendix C to the Kinder Morgan, Inc. 2000
         Proxy Statement on Schedule 14-A)

             1994 Amended and Restated Kinder Morgan, Inc. Long-term Incentive
         Plan (Appendix A to the Kinder Morgan, Inc. 2000 Proxy Statement on
         Schedule 14A)

             K N Energy, Inc. Nonqualified Deferred Compensation Plan*

             Letter Agreement dated December 4, 1995 between K N Energy, Inc.
         and Charles W. Battey (Exhibit 10(q) to the Annual Report on Form 10-K
         for the year ended December 31, 1995)

             Form of Incentive Stock Option Agreement (Exhibit 10(v) to the
         Annual Report on Form 10-K for the year ended December 31, 1996)

             Form of Restricted Stock Agreement (Exhibit 10(w) to the Annual
         Report on Form 10-K for the year ended December 31, 1996)

             Directors and Executives Deferred Compensation Plan effective
         January 1, 1998 for executive officers and directors of K N Energy,
         Inc. (Exhibit 10(aa) to the Annual Report on Form 10-K for the year
         ended December 31, 1998)

             Management Deferred Compensation Plan effective January 1, 1998
         for senior management of K N Energy, Inc. (Exhibit 10(bb) to the
         Annual Report on Form 10-K for the year ended December 31, 1998)

             Confidentiality Agreement and General Release between Larry D.
         Hall and KN Energy, Inc. dated October 4, 1999*

             Employment Agreement dated October 7, 1999, between the Company
         and Richard D. Kinder (incorporated by reference to Exhibit 99.D of
         the Schedule 13D filed by Mr. Kinder on October 8, 1999)

             Kinder Morgan, Inc. Amended and Restated 1999 Stock Option Plan
         (Appendix B to the Kinder Morgan, Inc. 2000 Proxy Statement on
         Schedule 14A)


                                      -2-

<PAGE>   3



             Kinder Morgan, Inc. Employees Stock Purchase Plan (Appendix E to
         the Kinder Morgan, Inc. 2000 Proxy Statement on Schedule 14A)

             2000 Annual Incentive Plan of Kinder Morgan, Inc. (Appendix D to
         the Kinder Morgan, Inc. 2000 Proxy Statement on Schedule 14A)

         *Filed herewith.


Subsection (b) of Item 14 entitled "Reports on Form 8-K" which was previously
filed with the Form 10-K is hereby amended and supplemented by adding the
following paragraph at the end of the subsection:

         Current Report on Form 8-K dated April 5, 2000, was filed on April 20,
         2000, pursuant to Item 2 and Item 7 of that form. Pursuant to Item 2
         of that form, Kinder Morgan disclosed that Kinder Morgan and certain
         of its subsidiaries had completed the disposition of certain assets to
         ONEOK, Inc. pursuant to an agreement dated as of February 8, 2000 with
         ONEOK, Inc., as amended on April 5, 2000. The agreement provided for
         the sale to ONEOK, Inc. of (i) all of Kinder Morgan's natural gas
         gathering and processing business in Oklahoma, Kansas and West Texas,
         (ii) Kinder Morgan's marketing and trading business, and (iii) certain
         of Kinder Morgan's storage and transmission pipelines in the
         mid-continent region. According to the agreement, ONEOK (i) paid
         approximately $108 million plus an amount equal to net working capital
         at closing, (ii) assumed the operating lease associated with the
         Bushton, Kansas gas processing plant and (iii) assumed long-term
         capacity commitments on NGPL and on KMIGT. Also, Kinder Morgan
         disclosed that on April 5, 2000, Kinder Morgan issued a press release.
         Pursuant to Item 7 of that form, the amendment to the agreement with
         ONEOK and the press release were filed as exhibits.

The Exhibit Index previously filed with the Form 10-K is hereby amended and
supplemented by replacing the current text in its entirety and substituting the
Exhibit Index filed herein.


                                      -3-

<PAGE>   4


                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) 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.

                                     KINDER MORGAN, INC.
                                       (Registrant)
Date: May 22, 2000
                                     By:  /s/ Joseph Listengart
                                         --------------------------------------
                                         Joseph Listengart
                                         Vice President, General Counsel
                                           and Secretary

Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following person on behalf of the
Registrant and in the capacities and on the date indicated.

<TABLE>
<S>                                                           <C>
                  *                                           Director
--------------------------------------------
         Edward H. Austin, Jr.

                  *                                           Director
--------------------------------------------
          Charles W. Battey

                  *                                           Director
--------------------------------------------
          Stewart A. Bliss

                  *                                           Director
--------------------------------------------
           Ted A. Gardner

                  *                                           Director
--------------------------------------------
           William J. Hybl

                  *
--------------------------------------------                  Chairman, Chief Executive Officer and
          Richard D. Kinder                                     and Director (Principal Executive Officer)


                  *                                           Vice Chairman, President and Director
--------------------------------------------
          William V. Morgan

                  *                                           Director
--------------------------------------------
         Edward Randall, III

                  *                                           Director
--------------------------------------------
            Fayez Sarofim

                  *
--------------------------------------------                  Vice President and Chief Financial Officer
            C. Park Shaper                                    (Principal Financial and Accounting Officer)


                  *                                           Director
--------------------------------------------
           H. A. True, III

*By: /s/ Joseph Listengart
     ------------------------------------------
         Joseph Listengart
        (Attorney-in-fact for persons indicated)
</TABLE>




                                      -4-

<PAGE>   5


                                 EXHIBIT INDEX

<TABLE>
<CAPTION>
EXHIBIT
  NO.             DESCRIPTION
-------           -----------
<S>          <C>  <C>
                  List of Executive Compensation Plans and Arrangements.........2-3

Exhibit 2(a)   -  Agreement and Plan of Merger, dated as of July 8,
                  1999, by and among K N Energy, Inc., Rockies Merger Corp.,
                  and Kinder Morgan, Inc., (Annex A-1 of Registration Statement
                  on Form S-4 (File No. 333-85747))

Exhibit 2(b)   -  First Amendment to Agreement and Plan of Merger, dated
                  as of August 20, 1999, by and among K N Energy, Inc.,
                  Rockies Merger Corp., and Kinder Morgan, Inc., (Annex A-2 of
                  Registration Statement on Form S-4 (File No. 333-85747))

Exhibit 2(c)   -  Contribution Agreement, dated as of December 30, 1999,
                  by and among Kinder Morgan, Inc., Natural Gas Pipeline
                  Company of America, K N Gas Gathering, Inc., Kinder Morgan
                  G.P., Inc. and Kinder Morgan Energy Partners, L.P. (Exhibit
                  99.1 to Current Report on Form 8-K filed on January 14, 2000)

Exhibit 3(a)   -  Restated Articles of Incorporation of Kinder Morgan, Inc.*

Exhibit 3(b)   -  Certificate of Amendment to the Restated Articles of
                  Incorporation of Kinder Morgan, Inc. as filed on October 7,
                  1999, with the Secretary of State of Kansas (Exhibit 3.1 to
                  Kinder Morgan, Inc.'s Quarterly Report on Form 10-Q for the
                  quarter ended September 30, 1999)

Exhibit 3(c)   -  Bylaws of Kinder Morgan, Inc., as amended to October 7, 1999
                  (Exhibit 3.2 to Kinder Morgan, Inc.'s Quarterly Report on
                  Form 10-Q for the quarter ended September 30, 1999)

Exhibit 4(a)   -  Indenture dated as of September 1, 1988, between K N Energy,
                  Inc. and Continental Illinois National Bank and Trust Company
                  of Chicago*

Exhibit 4(b)   -  First supplemental indenture dated as of January 15, 1992,
                  between K N Energy, Inc. and Continental Illinois National
                  Bank and Trust Company of Chicago (Exhibit 4.2, File No.
                  33-45091)

Exhibit 4(c)   -  Second supplemental indenture dated as of December 15, 1992,
                  between K N Energy, Inc. and Continental Bank, National
                  Association*

Exhibit 4(d)   -  Indenture dated as of November 20, 1993, between K N Energy,
                  Inc. and Continental Bank, National Association (Exhibit 4.1,
                  File No. 33-51115) Note - Copies of instruments relative to
                  long-term debt in authorized amounts that do not exceed 10
                  percent of the consolidated total assets of Kinder Morgan and
                  its subsidiaries have not been furnished. Kinder Morgan will
                  furnish such instruments to the Commission upon request.

Exhibit 4(e)   -  $600,000,000 364-Day Credit Agreement among K N Energy, Inc.,
                  certain banks listed therein and Morgan Guaranty Trust
                  Company of New York as Administrative Agent (Exhibit 4(e) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1997)

Exhibit 4(f)   -  $400,000,000 Five-Year Credit Agreement among K N Energy,
                  Inc., certain banks listed therein and Morgan Guaranty Trust
                  Company of New York as Administrative Agent (Exhibit 4(f) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1997)
</TABLE>


<PAGE>   6



<TABLE>
<S>          <C>  <C>

Exhibit 4(g)  -   $2,100,000,000 364-Day Credit Agreement among K N Energy,
                  Inc., certain banks listed therein and Morgan Guaranty Trust
                  Company of New York as Administrative Agent (Exhibit 4(g) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1997)

Exhibit 4(h)  -   $1,394,846,122 Reimbursement Agreement among K N Energy, Inc.,
                  certain banks listed therein and Morgan Guaranty Trust
                  Company of New York as Administrative Agent (Exhibit 4(e) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1997)

Exhibit 4(i)  -   Purchase Contract Agreement dated as of November 25, 1998,
                  between K N Energy, Inc. and U.S. Bank Trust National
                  Association, as Purchase Contract Agent for the PEPS Units
                  (Exhibit 4.4 to the Current Report on Form 8-K dated November
                  24, 1998)

Exhibit 4(j)  -   Amendment No. 1 to Credit Agreements dated as of November 6,
                  1998, among K N Energy, Inc., certain banks listed therein
                  and Morgan Guaranty Trust Company of New York as
                  Administrative Agent (Exhibit 4(j) to the Annual Report on
                  Form 10-K for the year ended December 31, 1998)

Exhibit 4(k)  -   $600,000,000 364-Day Credit Agreement dated as of January 8,
                  1999, among K N Energy, Inc., certain banks listed therein
                  and Morgan Guaranty Trust Company of New York as
                  Administrative Agent (Exhibit 4(k) to the Annual Report on
                  Form 10-K for the year ended December 31, 1998)

Exhibit 4(l)  -   Amendment No. 2 to the $400,000,000 Five-Year Credit
                  Agreement, dated as of January 8, 1999, among K N Energy,
                  Inc., certain banks listed therein and Morgan Guaranty Trust
                  Company of New York as Administrative Agent (Exhibit 4(l) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1998)

Exhibit 4(m)  -   $550,000,000 364-day Credit Agreement, dated as of November
                  18, 1999, among Kinder Morgan, Inc., certain banks listed
                  therein and Bank of America, N.A., as Administrative Agent
                  (Exhibit 4(m) to the Annual Report on Form 10-K for the year
                  ended December 31, 1999)

Exhibit 4(n)  -   Rights Agreement between K N Energy, Inc. and the Bank of New
                  York, as Rights Agent, dated as of August 21, 1995 (Exhibit 1
                  on Form 8-A dated August 21, 1995)

Exhibit 4(o)  -   Amendment No. 1 to Rights Agreement between K N Energy, Inc.
                  and the Bank of New York, as Rights Agent, dated as of
                  September 8, 1998 (Exhibit 10(cc) to the Annual Report on
                  Form 10-K for the year ended December 31, 1998)

Exhibit 4(p)  -   Amendment No. 2 to Rights Agreement of Kinder Morgan, Inc.
                  dated July 8, 1999, between Kinder Morgan, Inc. and First
                  Chicago Trust Company of New York, as successor-in-interest
                  to the Bank of New York, as Rights Agent (Exhibit 4.1 to
                  Kinder Morgan, Inc.'s Quarterly Report on Form 10-Q for the
                  quarter ended September 30, 1999)
</TABLE>



<PAGE>   7




<TABLE>
<S>           <C>    <C>
Exhibit 10(a)  -  1987 Directors' Deferred Fee Plan As Amended and Form of
                  Participation Agreement regarding the Plan (Exhibit 10(h) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1995)

Exhibit 10(b)  -  Kinder Morgan, Inc. Amended and Restated 1992 Stock Option
                  Plan for Nonemployee Directors (Appendix C to the Kinder
                  Morgan, Inc. 2000 Proxy Statement on Schedule 14A)

Exhibit 10(c)  -  1994 Amended and Restated Kinder Morgan, Inc. Long-term
                  Incentive Plan (Appendix A to the Kinder Morgan, Inc. 2000
                  Proxy Statement on Schedule 14A)

Exhibit 10(d)  -  K N Energy, Inc. Nonqualified Deferred Compensation Plan*

Exhibit 10(e)  -  Letter Agreement dated December 4, 1995 between K N Energy,
                  Inc. and Charles W. Battey (Exhibit 10(q) to the Annual
                  Report on Form 10-K for the year ended December 31, 1995)

Exhibit 10(f)  -  Kinder Morgan, Inc. Employees Stock Purchase Plan (Appendix E
                  to the Kinder Morgan, Inc. 2000 Proxy Statement on Schedule
                  14A)

Exhibit 10(g)  -  2000 Annual Incentive Plan of Kinder Morgan, Inc. (Appendix D
                  to the Kinder Morgan, Inc. 2000 Proxy Statement on Schedule
                  14A)

Exhibit 10(h)  -  Confidentiality Agreement and General Release between
                  Larry D. Hall and K N Energy, Inc. dated October 4, 1999*

Exhibit 10(i)  -  Amended and Restated Basket Agreement dated as of June 30,
                  1990, by and between American Pipeline Company ("APC"), Cabot
                  and Cabot Transmission Corporation*

Exhibit 10(j)  -  First Amendment to Amended and Restated Omnibus Acquisition
                  Agreement and Amended and Restated Basket Agreement dated as
                  of March 31, 1992, by and among AOG, APC, Cabot and Cabot
                  Transmission*

Exhibit 10(k)  -  Form of Incentive Stock Option Agreement (Exhibit 10(v) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1996)

Exhibit 10(l)  -  Form of Restricted Stock Agreement (Exhibit 10(w) to the
                  Annual Report on Form 10-K for the year ended December 31,
                  1996)

Exhibit 10(m)  -  Intrastate Pipeline System Lease, dated December 31, 1996,
                  between MidCon Texas Pipeline, L.P. and MidCon Texas Pipeline
                  Operator, Inc. (Exhibit 10(y) to the Annual Report on Form
                  10-K for the year ended December 31, 1997)

Exhibit 10(n)  -  Amendment Number One To Intrastate Pipeline System Lease,
                  dated January 31, 1998, between MidCon Texas Pipeline, L.P.
                  and MidCon Texas Pipeline Operator, Inc. (Exhibit 10(z) to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1997)

Exhibit 10(o)  -  Directors and Executives Deferred Compensation Plan effective
                  January 1, 1998 for executive officers and directors of K N
                  Energy, Inc. (Exhibit 10(aa) to the Annual Report on Form
                  10-K for the year ended December 31, 1998)
</TABLE>


<PAGE>   8



<TABLE>
<S>           <C> <C>
Exhibit 10(p) -   Management Deferred Compensation Plan effective January 1,
                  1998 for senior management of K N Energy, Inc. (Exhibit
                  10(bb) to the Annual Report on Form 10-K for the year ended
                  December 31, 1998)

Exhibit 10(q) -   Kinder Morgan, Inc. Amended and Restated 1999 Stock Option
                  Plan (Appendix B to the Kinder Morgan, Inc. 2000 Proxy
                  Statement on Schedule 14A)

Exhibit 10(r) -   Stock Purchase Agreement, dated December 18, 1997, between
                  K N Energy, Inc. and Occidental Petroleum Corporation (Exhibit
                  2.1, File No. 333-44421)

Exhibit 10(s) -   Amendment No. 1 to Stock Purchase Agreement, dated January
                  30,1998, between K N Energy, Inc. and Occidental Petroleum
                  Corporation (Exhibit 2(b) to the Annual Report on Form 10-K
                  for the year ended December 31, 1997)

Exhibit 10(t) -   Governance Agreement dated October 7, 1999, between Kinder
                  Morgan, Inc. and Richard D. Kinder (Exhibit 99.C of the
                  Schedule 13D filed by Mr. Kinder on October 8, 1999)

Exhibit 10(u) -   Governance Agreement dated October 7, 1999, between Kinder
                  Morgan, Inc. and Morgan Associates, Inc. (Exhibit 99.C of the
                  Schedule 13D filed by Morgan Associates, Inc. and William V.
                  Morgan on October 8, 1999)

Exhibit 10(v) -   Employment Agreement dated October 7, 1999, between the
                  Company and Richard D. Kinder (Exhibit 99.D of the
                  Schedule 13D filed by Mr. Kinder on October 8, 1999)

Exhibit 10(w) -   Receivables Purchase Agreement dated September 28, 1999,
                  among K N Receivables Corporation, as Seller, Falcon Asset
                  Securitization Corporation, International Securitization
                  Corporation and The Financial Institutions Party Hereto, as
                  Investors and Bank One, NA, as agent (Exhibit 10.4 to Kinder
                  Morgan, Inc.'s Quarterly Report on Form 10-Q for the quarter
                  ended September 30, 1999)

Exhibit 10(x) -   Receivables Sale Agreement dated September 28, 1999, between
                  K N Energy, Inc., as the Originator, and other Originators
                  specified herein and K N Receivables Corporation, as Buyer
                  (Exhibit 10.5 to Kinder Morgan, Inc.'s Quarterly Report on
                  Form 10-Q for the quarter ended September 30, 1999)

Exhibit 13    -   1999 Annual Report to Shareholders (Exhibit 13 to the Annual
                  Report on Form 10-K for the year ended December 31, 1999)

Exhibit 21    -   Subsidiaries of the Registrant (Exhibit 21 to the Annual
                  Report on Form 10-K for the year ended December 31, 1999)

Exhibit 23.1  -   Consent of Independent Accountants (Exhibit 23.1 to the
                  Annual Report on Form 10-K for the year ended December 31,
                  1999)

Exhibit 23.2  -   Consent of Independent Public Accountants (Exhibit 23.2 to
                  the Annual Report on Form 10-K for the year ended December
                  31, 1999)

Exhibit 24.1  -   Power of Attorney*

Exhibit 27    -   Financial Data Schedule (Exhibit 27 to the Annual Report on
                  Form 10-K for the year ended December 31, 1999)
</TABLE>

*  Filed herewith.