<PAGE>
                                                                    EXHIBIT 4(d)



                       FIRST AMENDMENT TO CREDIT AGREEMENT


         This First Amendment to Credit Agreement (the "Amendment") is made as
of July 22, 2002, by and among CERNER CORPORATION, a Delaware corporation (the
"Borrower"); U.S. BANK NATIONAL ASSOCIATION, a national banking association, in
its capacity as Administrative Agent, Lead Arranger, Swingline Lender, Issuing
Bank and a Bank; LASALLE BANK NATIONAL ASSOCIATION, a national banking
association, in its capacity as Documentation Agent and a Bank; COMMERCE BANK,
N.A., a national banking association, in its capacity as a Bank; and UMB BANK,
N.A., a national banking association, in its capacity as a Bank. Capitalized
terms used and not defined hereunder have the meanings given to them in the
Credit Agreement referred to below.

                             Preliminary Statements

         (a) The Borrower and the Bank Parties are parties to a Credit Agreement
dated as of May 31, 2002 (the "Credit Agreement").

         (b) The Borrower has requested that, among other things, (1) Section
6.11 of the Credit Agreement be amended to permit the Borrower to redeem a
portion of its stock from time to time, (2) Section 2.3 of the Credit Agreement
be amended to address Foreign Currency Letters of Credit, and (3) in connection
with a proposed Acquisition by the Borrower, the Bank Parties waive the
Borrower's obligation to comply with certain provisions of Section 6.10(d)(3) of
the Credit Agreement. The Bank Parties are willing to agree to the foregoing
requests, subject, however, to the terms, conditions and agreements set forth
below.

         NOW, THEREFORE, the parties agree as follows:

         1. DEFINITIONS. Section 1.1 of the Credit Agreement is amended to add
the following defined terms:

                  "Bank Parties" shall mean U.S. Bank National Association, in
         its capacity as Administrative Agent, Lead Arranger, Issuing Bank,
         Swingline Lender and a Bank; LaSalle Bank National Association, in its
         capacity as Documentation Agent and a Bank; Commerce Bank, N.A., in its
         capacity as a Bank; and UMB Bank, N.A., in its capacity as a Bank. Use
         of the term "Bank Parties" in any of the Credit Documents is for
         convenience of reference only, and shall not impose or alter any
         requirement under any of the Credit Documents regarding which Persons
         must consent to which matters or in which capacity a Person must act in
         consenting to a matter or in taking any other action.

                  "First Amendment" shall mean the First Amendment to Credit
         Agreement, dated as of July 22, 2002, among the Borrower and the Bank
         Parties.

                  "Foreign Currency Letter of Credit" shall mean any Letter of
         Credit denominated in a currency other than Dollars.




                  First Amendment to Credit Agreement -- Page 1
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         2. STOCK REDEMPTIONS. Section 6.11 of the Credit Agreement is deleted
and is replaced with the following:

                  6.11. Dividends and Distributions. The Borrower shall not, nor
         shall it permit any of its Subsidiaries to, declare or pay, directly or
         indirectly, any dividend or make any other distribution (by reduction
         of capital or otherwise), whether in cash, property, securities or
         otherwise, with respect to any shares of its capital stock or directly
         or indirectly redeem, purchase, retire or otherwise acquire for value
         any shares of any class of its capital stock or set aside any amount
         for any such purpose (the foregoing transactions being collectively
         called "Restricted Payments"); provided, however, that (a) the Borrower
         and its Subsidiaries may declare and pay dividends payable solely in
         shares of its common stock, (b) any Subsidiary of the Borrower may make
         Restricted Payments to the Borrower or to any Guarantor Subsidiary, and
         (c) the Borrower may declare and pay cash dividends, and/or redeem,
         purchase, retire or otherwise acquire for value any shares of any class
         of its capital stock or set aside any amount for any such purpose, in
         each case if (1) no Default or Event of Default then exists or would
         result therefrom, and (2) the aggregate amount of such cash dividends
         paid during any fiscal quarter, together with the aggregate amount of
         all capital stock redeemed, purchased, retired or otherwise acquired
         during such fiscal quarter, does not exceed 50% of Consolidated Net
         Income for the four fiscal quarters most recently ended.

         3. FOREIGN CURRENCY LETTERS OF CREDIT. A new Section 2.3(k) is added to
the Credit Agreement which reads as follows:

                  (k) The Borrower may request that Letters of Credit be issued
         as Foreign Currency Letters of Credit (meaning that such Letters of
         Credit are denominated in a currency other than Dollars). If the
         aggregate undrawn face amount of all Foreign Currency Letters of Credit
         exceeds $10,000,000 at any time, then the Borrower shall enter into one
         or more foreign currency hedging, swap or similar agreements
         (collectively, a "Foreign Currency Swap Agreement") with the Issuing
         Bank or other Person reasonably acceptable to the Issuing Bank (each, a
         "Counterparty"), in each case reasonably acceptable in form and content
         to the Administrative Agent, with respect to all Foreign Currency
         Letters of Credit then or thereafter outstanding, whereby, in return
         for the Borrower paying hedging, swap or similar fees to the
         Counterparty, the Counterparty assumes substantially all of the risk of
         any decline in the value of the Dollar relative to the applicable
         foreign currency for the duration of the term of such Foreign Currency
         Letters of Credit. The Borrower shall maintain such Foreign Currency
         Swap Agreement so long as the aggregate undrawn face amount of all
         Foreign Currency Letters of Credit outstanding exceeds $10,000,000. If
         the Borrower's foreign currency exposure with respect to Foreign
         Currency Letters of Credit is not fully hedged pursuant to a Foreign
         Currency Swap Agreement reasonably acceptable to the Administrative
         Agent, then (1) the Borrower agrees to reimburse the Issuing Bank, for
         the benefit of the Banks pursuant to their respective Pro-Rata Shares,
         for all currency fluctuation losses incurred by the Issuing Bank or any
         Bank in connection with any


                  First Amendment to Credit Agreement -- Page 2

<PAGE>

         decline in the value of the Dollar relative to the applicable foreign
         currency at the time of any draw or other payment made under any
         Foreign Currency Letter of Credit, and (2) the Administrative Agent,
         acting in a commercially reasonable manner, shall have the right to
         periodically mark to market or otherwise adjust the LC Exposure of the
         Banks to reflect any such foreign currency fluctuation, and accordingly
         to reduce the amount of credit available to the Borrower under this
         Agreement because of such foreign currency fluctuation. The
         Administrative Agent, the Issuing Bank and the Banks shall have the
         rights set forth in the preceding sentence notwithstanding that the
         aggregate undrawn face amount of all Foreign Currency Letters of Credit
         outstanding is less than $10,000,000 at any time.

         4. COVENANT WAIVER; SELECTED 2002 ACQUISITIONS. The Borrower has
advised the Bank Parties that the Borrower intends to make an Acquisition, on or
before October 31, 2002, of a foreign entity who is in the same line of business
of the Borrower and that the aggregate amount of consideration payable by the
Borrower at any time in respect of such Acquisition will not exceed $17,000,000
(the "Proposed Foreign 2002 Acquisition;" the Proposed Foreign 2002 Acquisition,
together with the Borrower's earlier acquisition in 2002 of Zynx Health
Incorporated, are collectively referred to herein as the "Combined 2002
Acquisitions"). Based upon the foregoing, the Bank Parties hereby waive any
Default or Event of Default under Section 6.10(d)(3) of the Credit Agreement
arising solely as a result of the aggregate amount of cash and all other
consideration (including, without limitation, assumed or Guaranteed
Indebtedness, but excluding equity securities of the Borrower) payable at any
time in respect of the Combined 2002 Acquisitions exceeding 5% of the
Consolidated Net Worth of the Borrower and its Subsidiaries (as reflected in the
financial statements of such Persons, dated most recently prior to the
consummation of the Proposed Foreign 2002 Acquisition, delivered to the
Administrative Agent pursuant to Section 6.1 of the Credit Agreement); provided,
however, that the foregoing waiver shall not be effective if (a) the aggregate
amount of consideration payable by the Borrower at any time in respect of the
Proposed Foreign 2002 Acquisition exceeds $17,000,000, or (b) the Proposed
Foreign 2002 Acquisition is not consummated in all material respects on or
before October 31, 2002.

         5. CONDITIONS PRECEDENT TO AMENDMENT. Notwithstanding anything in this
Amendment to the contrary, unless and to the extent the Administrative Agent
waives the benefits of this sentence by giving written notice thereof to the
Borrower, none of the Bank Parties shall have any duties under this Amendment,
nor shall any waivers, releases or other concessions, if any, made or given by
any of the Bank Parties under this Amendment be effective, in each case until
the Administrative Agent has received fully executed originals of each of the
following, each in form and substance satisfactory to the Administrative Agent:

                  (a) AMENDMENT. This Amendment;

                  (b) OTHER. Such other documents as the Administrative Agent
         may reasonably request in connection with the transactions contemplated
         hereby.

         6. REPRESENTATIONS AND WARRANTIES. The Borrower represents and warrants
to the Bank Parties as follows: (a) it is a duly organized and validly existing
corporation and has full corporate power and authority to enter into this
Amendment and any documents or transactions contemplated hereby and to pay and
perform its obligations in respect of each of the foregoing; (b) the execution,
delivery and performance by the Borrower of this Amendment and any documents
contemplated hereby or any transactions contemplated hereby do not violate or
conflict with, or require any consent under, (i) the Borrower's certificate of
incorporation, by-laws, or any other agreement or document relating to the
Borrower's existence or authority to act, (ii) any agreement or instrument to
which the Borrower is a party or by which the Borrower or any of its properties
is bound, (iii) any court order, judicial proceeding or any administrative or
arbitral order or decree,



                  First Amendment to Credit Agreement -- Page 3

<PAGE>

or (iv) any applicable law, rule or regulation; and (c) no authorization,
approval or consent of or by, and no notice to or filing or registration with,
any governmental authority or any other Person is necessary for the Borrower to
enter into this Amendment or any document contemplated hereby or any transaction
contemplated hereby or to perform its obligations with respect to each of the
foregoing.

         7. REAFFIRMATION OF CREDIT DOCUMENTS. The Borrower reaffirms its
obligations under the Credit Agreement and the other Credit Documents to which
it is a party or by which it is bound, and represents, warrants and covenants to
the Bank Parties, as a material inducement to the Bank Parties to enter into
this Amendment and the transactions contemplated hereby, that (a) the Borrower
has no (and, in any event, hereby waives any) defense, claim or right of setoff
in respect of the Credit Agreement, any of the other Credit Documents or the
actions or inactions of any of the Bank Parties; and (b) all representations and
warranties made by the Borrower in the Credit Agreement and the other Credit
Documents are true and complete on the date hereof as if made on the date
hereof, except for any such representations or warranties which specifically and
expressly relate to an earlier date, which representations and warranties were
true and complete as of such earlier date.

         8. NO OTHER AMENDMENTS. Except as amended hereby, the Credit Agreement
and the other Credit Documents shall remain in full force and effect and be
binding on the Borrower in accordance with their respective terms.

         9. COUNTERPARTS; FAX SIGNATURES. This Amendment and any document
contemplated hereby may be executed in one or more counterparts and by different
parties thereto, all of which counterparts, when taken together, shall
constitute but one agreement. This Amendment and any document contemplated
hereby may be executed and delivered by facsimile or other electronic
transmission, and any such execution or delivery shall be fully effective as if
executed and delivered in person.

         10. LEGAL FEES. The Borrower shall pay the reasonable legal fees and
expenses incurred by the Administrative Agent in connection with the preparation
and closing of this Amendment and any other documents referred to herein and the
consummation of any transactions referred to herein.

         11. MO.REV.STAT. SECTION 432.045 REQUIRED NOTICE. The following
statement is given pursuant to Mo.Rev.Stat. Section 432.045: "ORAL AGREEMENTS OR
COMMITMENTS TO LOAN MONEY, EXTEND CREDIT OR TO FORBEAR FROM ENFORCING REPAYMENT
OF A DEBT INCLUDING PROMISES TO EXTEND OR RENEW SUCH DEBT ARE NOT ENFORCEABLE.
TO PROTECT YOU (BORROWER(S)) AND US (CREDITOR) FROM MISUNDERSTANDING OR
DISAPPOINTMENT, ANY AGREEMENTS WE REACH COVERING SUCH MATTERS ARE CONTAINED IN
THIS WRITING, WHICH IS THE COMPLETE AND EXCLUSIVE STATEMENT OF THE AGREEMENT
BETWEEN US, EXCEPT AS WE MAY LATER AGREE IN WRITING TO MODIFY IT." All other
Credit Documents are incorporated into this Amendment; provided, however, that,
to the extent of any direct conflict between the terms and conditions of the
other Credit Documents and this Amendment, the terms and conditions of this
Amendment shall prevail and govern.

         12. GOVERNING LAW. This Amendment shall be governed by the laws of the
State of Missouri without regard to any choice of law rule thereof giving effect
to the laws of any other jurisdiction.



                          [signature page(s) to follow]



                  First Amendment to Credit Agreement -- Page 4
<PAGE>




         IN WITNESS WHEREOF, the parties have entered into this Amendment as of
the date first above written.


<Table>
<S>                                                <C>
CERNER CORPORATION                                 COMMERCE BANK, N.A., as a Bank



By: \s\ Marc G. Naughton                           By: \s\ Pamela T. Hill
   ------------------------------------               ---------------------------------
   Name:  Marc G. Naughton                            Name:  Pamela T. Hill
   Title:  CFO/Senior Vice President                  Title:  Vice President


U.S. BANK NATIONAL ASSOCIATION,                      UMB BANK, NA., as a Bank
as Administrative Agent, Lead Arranger,
Issuing Bank, Swingline Lender and a Bank



By: \s\ Mark R. Jorgenson                          By: \s\ Kevin E. Kramer
   ------------------------------------               ---------------------------------
   Name:  Mark R. Jorgenson                           Name:  Kevin E. Kramer
   Title:  SVP                                        Title:  Senior Vice President


LASALLE BANK NATIONAL ASSOCIATION,
as Documentation Agent and a Bank



By: \s\ James C. Binz
   ------------------------------------
   Name:  James C. Binz
   Title:  First Vice President
</Table>



                        [Consent of Guarantors to follow]



              First Amendment to Credit Agreement -- Signature Page

<PAGE>




                              CONSENT OF GUARANTORS


         Reference is made to the Guaranty dated as of May 31, 2002, in favor of
the Administrative Agent, on behalf of the Banks, the Swingline Lender and the
Issuing Bank, to which the undersigned (each a "Guarantor") are parties, either
as an original signatory thereto or pursuant to any subsequent assumption,
joinder or other agreements, and any other guaranty executed by any Guarantor in
favor of the Administrative Agent or any other Bank Party relating to any
indebtedness of the Borrower under any of the Credit Documents (collectively,
with respect to each Guarantor, such Guarantor's "Guaranty"). Capitalized terms
used and not defined in this Consent of Guarantors have the meanings given to
them in the Credit Agreement referred to in the above Amendment. To induce the
Bank Parties to enter into the above Amendment, each Guarantor: (a) consents to
the Borrower and the Bank Parties entering into the above Amendment; (b) agrees
that the execution, delivery and performance of the above Amendment and any
documents or transactions contemplated thereby shall not discharge, limit or
otherwise impair the obligations of such Guarantor under such Guarantor's
Guaranty; (c) agrees that such Guarantor's Guaranty is and remains in full force
and effect and is enforceable against such Guarantor in accordance with its
terms; (d) waives any defense, claim or right of setoff such Guarantor may have
in respect of such Guarantor's Guaranty, the Credit Agreement, the other Credit
Documents or the actions or inactions of any of the Bank Parties; and (e) agrees
that none of the Bank Parties has any duty to give such Guarantor notice of or
obtain such Guarantor's consent to the transactions described in the above
Amendment, and that the Bank Parties' giving of notice to such Guarantor and
obtainment of such Guarantor's consent in this instance shall not impose any
similar or other duty upon any of the Bank Parties in any future matter or
transaction. This Consent of Guarantors may be validly executed and delivered by
fax or other electronic transmission and in multiple counterparts and by
different parties thereto.


<Table>
<S>                                                <C>
CERNER PROPERTIES, INC.,                           CERNER INTERNATIONAL, INC.,
a Delaware corporation                             a Delaware corporation


By: \s\ Marc G. Naughton                           By: \s\ Marc G. Naughton
   ------------------------------------               ---------------------------------
   Name:  Marc G. Naughton                            Name:  Marc G. Naughton
   Title:  Vice President and Treasurer               Title:  Vice President and Treasurer

CERNER MULTUM, INC.,                                 CERNER HEALTH CONNECTIONS, INC.,
a Delaware corporation                                        a Delaware corporation


By: \s\ Marc G. Naughton                              By: \s\ Marc G. Naughton
   ------------------------------------               ---------------------------------
   Name:  Marc G. Naughton                            Name:  Marc G. Naughton
   Title:  Treasurer                                  Title:  Vice President and Treasurer
</Table>




              First Amendment to Credit Agreement -- Signature Page

<PAGE>


<Table>
<S>                                                <C>
CERNER HEALTH FACTS, INC.,                         CERNER CITATION, INC.,
a Delaware corporation                             a Delaware corporation


By: \s\ Marc G. Naughton                           By: \s\ Marc G. Naughton
   ------------------------------------               ---------------------------------
   Name:  Marc G. Naughton                            Name:  Marc G. Naughton
   Title:  Vice President and Treasurer               Title:  Vice President and Treasurer

CERNER INVESTMENT CORP.,                           HEALTH NETWORK VENTURES, INC.,
a Nevada corporation                               a Missouri corporation


By: \s\ Marc G. Naughton                           By: \s\ Marc G. Naughton
   ------------------------------------               ---------------------------------
   Name:  Marc G. Naughton                            Name:  Marc G. Naughton
   Title:  Vice President and Treasurer               Title:  Vice President and Treasurer


CERNER CAMPUS REDEVELOPMENT                        CERNER RADIOLOGY
CORPORATION,                                       INFORMATION SYSTEMS, INC.,
a Missouri corporation                             a Texas corporation


By: \s\ Marc G. Naughton                           By: \s\ Marc G. Naughton
   ------------------------------------               ---------------------------------
   Name:  Marc G. Naughton                            Name:  Marc G. Naughton
   Title:   Treasurer                                 Title:

ZYNX HEALTH INCORPORATED,                          CERNER DHT, INC.,
a California corporation                           a Delaware corporation


By: \s\ Marc G. Naughton                           By: \s\ Marc G. Naughton
   ------------------------------------               ---------------------------------
   Name:  Marc G. Naughton                            Name:  Marc G. Naughton
   Title:  Treasurer                                  Title:  Vice President and Treasurer
</Table>




              First Amendment to Credit Agreement -- Signature Page