<PAGE>   1
                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    FORM 10-K
                                AMENDMENT NO. 1

                  (Mark One)

     [X]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
          EXCHANGE ACT OF 1934

                   For the Fiscal Year Ended December 31, 1998

                                       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 No.: 333-43021

                                    VIB CORP

             Incorporated Under the Laws of the State of California

                 I.R.S. EMPLOYER IDENTIFICATION NO.: 33-0780371

                                1498 MAIN STREET
                           EL CENTRO, CALIFORNIA 92243
                            TELEPHONE: (760) 337-3200

     Securities registered under Section 12(b) of the Exchange Act: None

     Securities registered under Section 12(g) of the Exchange Act: Common
     Stock, No Par Value
                                             Warrants (to purchase Common Stock)

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

     Aggregate market value of the voting Common Stock held by non-affiliates at
March 5, 1999: $97,381,000

     Number of shares of Common Stock outstanding as of March 5, 1999:
10,527,689

                       DOCUMENTS INCORPORATED BY REFERENCE

     Portions of the following documents are incorporated by reference into the
identified parts of this Form 10-K:

    VIB CORP's 1998 Annual Report to Shareholders - Part II, Items 5 and 6.

    1999 Annual Meeting Proxy Statement - Part III, Items 10, 11, 12 and 13.






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                                    VIB CORP



          This Amendment to Form 10-K Annual Report is being submitted for the 
purpose of electronically filing information regarding the Company's Common 
Stock inadvertently omitted from Exhibit 13 in the original submission. Exhibit 
13 is hereby amended by adding the attached information taken from the 
Company's Annual Report to Shareholders.
<PAGE>   3
                                   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.

                                       VIB CORP


Date: March 30, 1999                   By: /s/ Harry G. Gooding, III     
                                           -------------------------------------
                                           Harry G. Gooding, III,
                                           Executive Vice President and
                                           Chief Financial Officer

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

<TABLE>
<CAPTION>
Signature                                     Title                                    Date
---------                                     -----                                    ----
<S>                                           <C>                                      <C>


/s/ Charles Ellis                             Director                                 March 30, 1999
-------------------------
Charles Ellis


/s/ Robert S. Ellison                         Director                                 March 30, 1999
-------------------------
Robert S. Ellison


/s/ Richard D. Foss                           Chairman of the Board                    March 30, 1999
-------------------------                     of Directors
Richard D. Foss          


/s/ Harry G. Gooding, III                     Executive Vice President                 March 30, 1999
-------------------------                     and Chief Financial
Harry G. Gooding, III                         Officer (and Principal
                                              Accounting Officer)

/s/ Ed L. Hickman                             Director                                 March 30, 1999
-------------------------
Ed L. Hickman


/s/ Dennis L. Kern                            Director, President and                  March 30, 1999
-------------------------                     Chief Executive Officer
Dennis L. Kern                         


/s/ Edward McGrew                             Director                                 March 30, 1999
-------------------------
Edward McGrew


/s/ Ronald A. Pedersen                        Vice Chairman of the                     March 30, 1999
-------------------------                     Board of Directors
Ronald A. Pedersen                            


/s/ John L. Skinner                           Director                                 March 30, 1999
-------------------------
John L. Skinner

/s/ Alice Helen
Lowery Westerfield                            Vice Chairman of the                     March 30, 1999
-------------------------                     Board of Directors
Alice Helen Lowery       
  Westerfield
</TABLE>


                                       
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                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
REG. S-K,                                                                                           PAGE (OR
ITEM 601                                                                                            FOOTNOTE
EXHIBIT NO.   DESCRIPTION                                                                           REFERENCE)
-----------   -----------                                                                           ----------
<S>           <C>                                                                                   <C>

2.1           Plan of Reorganization and Merger Agreement, dated November 18, 1997,
              by and between Valley Independent Bank and VIB Merger Company................................(1)
2.2           Agreement and Plan of Reorganization by and between VIB Corp and
              Bank of Stockdale, F.S.B. dated September 15, 1998...........................................(2)
3.1           Articles of Incorporation of VIB Corp, as amended............................................(3)
3.2           Bylaws of VIB Corp...........................................................................(4)
4.1           Form of Common Stock Certificate.............................................................(5)
4.2           Form of Warrant Certificate .................................................................(5)
4.3           Junior Subordinated Indenture dated as of February 5, 1999 by and
              between the Registrant and Wilmington Trust Company, as trustee..............................(6)
4.4           Form of Junior Subordinate Debenture included in Article Two of
              Exhibit 4.3..................................................................................(6)
4.5           Trust Agreement of Valley Capital Trust dated as of December 10, 1998
              (included as Exhibit A to Exhibit 4.6).......................................................(6)
4.6           Amended and Restated Trust Agreement of Valley Capital Trust dated as
              of February 5, 1999 among the Registrant, Wilmington Trust Company, as
              Property Trustee, and Richard D. Foss, Harry G. Gooding, III, and Dennis
              L. Kern, as Administrative Trustees..........................................................(6)
4.7           Form of Common Security Certificate of Valley Capital Trust (included as
              Exhibit B to Exhibit 4.6)....................................................................(6)
4.8           Form of Capital Security Certificate of Valley Capital Trust (included as
              Exhibit C to Exhibit 4.6)....................................................................(6)
4.9           Guarantee Agreement dated February 5, 1999 between the Registrant, as
              Guarantor, and Wilmington Trust Company, as Guarantee Trustee................................(6)
4.10          Agreement as to Expenses and Liabilities dated February 5, 1999 between
              the Registrant and Valley Capital Trust......................................................(6)
10.1          Agreement to Assume Liabilities and to Acquire Branch Banking
              Office (Calexico)(P)........................................................................ (7)
10.2          Agreement and Plan of Reorganization Dated April 29, 1996
              (Bank of the Desert, N.A.)(P)................................................................(7)
10.3          Purchase and Assumption Agreement Dated October 15, 1996
              (Blythe and Tecate)(P).......................................................................(7)
10.4          VIB Corp 1997 Stock Option Plan..............................................................(4)
10.5          Form of VIB Corp Stock Option Agreement......................................................(4)
10.6          Form of VIB Corp Indemnity Agreement.........................................................(4)
10.7          Profit Sharing and 401(k) Plan(P)............................................................(7)
10.8          Amendment to 401(k) Plan(P)..................................................................(7)
10.9          1994 Amendments to 401(k) Plan(P)............................................................(7)
10.10         Employee Stock Ownership Plan(P).............................................................(7)
10.11         Form of Directors Deferred Compensation Agreement(P).........................................(7)
10.12         Form of Officers Deferred Compensation Agreement(P)..........................................(7)
10.13         El Centro Lease(P)...........................................................................(7)
10.14         Agreement to Assume Liabilities and to Acquire Assets of Branch Banking
              Office Dated January 22, 1998 (Palm Springs)..................................................*
</TABLE>



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                            EXHIBIT INDEX (CONTINUED)


<TABLE>
<CAPTION>
REG. S-K,                                                                                           PAGE (OR
ITEM 601                                                                                            FOOTNOTE
EXHIBIT NO.   DESCRIPTION                                                                           REFERENCE)
-----------   -----------                                                                           ----------
<S>           <C>                                                                                   <C>

10.15         Agreement to Assume Liabilities and to Acquire Assets of Branch
              Office between Fremont Investment & Loan and Valley Independent
              Bank dated September 22, 1998............................................................. (2)
13            VIB Corp's 1998 Annual Report to Shareholders (incorporated
              portions only)............................................................................ (8)**
21            Subsidiaries of the Registrant............................................................  *
23            Consents of Experts and Counsel...........................................................  *
27            Financial Data Schedule...................................................................  *
</TABLE>

---------
(1)      Filed as Exhibit "A" to the Proxy Statement/Prospectus included in the
         Registrant's Registration Statement on Form S-4 dated December 23, 1997
         (the "1997 S-4 Registration Statement").
(2)      Filed as an exhibit to the Registrant's Form 8-K dated September 29,
         1998.
(3)      Filed as an exhibit to the Registrant's Form 8-K dated May 1, 1998.
(4)      Filed as an exhibit to the 1997 S-4 Registration Statement.
(5)      Filed as an exhibit to the Registrant's Registration Statement on Form
         8-A dated March 19, 1998.
(6)      Filed as an exhibit to the Registrant's Form 8-K dated February 5,
         1999.
(7)      Filed as an exhibit to the Registrant's Form 10-K for the year ended
         December 31, 1997.
(8)      The Company's Annual Report to Shareholders, portions of which are
         incorporated by reference, will be submitted under separate cover.
         Except those portions incorporated by reference, the Annual Report to
         Shareholders is not to be deemed "filed" as a part of this Form 10-K.
         This exhibit is supplemented by this filing; a portion of this exhibit
         was previously filed.
(P)      Filed in paper format under cover of Form SE.


 * Previously filed.
** Filed herewith.