FIFTH AMENDMENT TO CREDIT AGREEMENT

Exhibit 99.1

FIFTH AMENDMENT TO CREDIT AGREEMENT

     This Fifth Amendment to Credit Agreement (the “ Amendment ”) is made as of December 28, 2005, 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, as amended by (1) a First Amendment to Credit Agreement dated as of July 22, 2002, (2) a Second Amendment to Credit Agreement dated as of April 30, 2003, (3) a Third Amendment to Credit Agreement dated as of September 1, 2004, and (4) a Fourth Amendment to Credit Agreement dated as of December 28, 2004 (as so amended, the “ Credit Agreement ”).

     (b) The Borrower has requested that certain provisions of the Credit Agreement dealing with the Borrower’s Subsidiaries be amended in certain respects. 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. Removal of Net Worth Restriction on Foreign Subsidiaries; New Domestic Net Worth Requirement. Section 6.9(c) of the Credit Agreement is deleted. A new Section 6.20 is added to the Credit Agreement which reads as follows:

     6.20 Consolidated Net Worth of Cerner and its Domestic Subsidiaries . The Borrower shall maintain, as of the last day of each fiscal quarter, a Consolidated Net Worth, for itself and its Subsidiaries (other than Foreign Subsidiaries), of not less than $500 million, plus beginning December 31, 2006, 50% of cumulative Consolidated Net Income (but not loss) since January 1, 2006 to the most recently ended fiscal year of the Borrower.

      2. Investments in Foreign Subsidiaries. Section 6.13(f)(5) of the Credit Agreement is deleted and is replaced by the following:

      3. Permitted Investment in Foreign Subsidiary Not Subject to Section 6.10 Asset Transfer Restrictions; Conforming Change. Section 6.10(e) of the Credit Agreement is deleted and is replaced by the following:

      4. Transactions with Affiliates. Section 6.15 of the Credit Agreement is deleted and is replaced by the following:

     6.15. Transactions With Affiliates . The Borrower shall not, and shall not permit any of its Subsidiaries to, directly or indirectly, (a) make any Investment in an Affiliate, (b) transfer, sell, lease, assign or otherwise dispose of any assets to an Affiliate, (c) merge or consolidate with or purchase or acquire any assets from an Affiliate, (d) Guarantee or assume any obligations of an Affiliate, or (e) enter into any other transaction directly or indirectly with or for the benefit of an Affiliate; provided that (1) any Affiliate who is an individual may serve as a director, officer or employee of the Borrower, or any of its Subsidiaries and receive compensation or indemnification in connection with his services in such capacity, (2) the Borrower or any Subsidiary may enter into any sale, license, lease or similar transaction with an Affiliate in the ordinary course of business if the monetary or business consideration arising therefrom would be not materially less advantageous to the Borrower or the Subsidiary as the monetary or business consideration which it would obtain in a comparable arm’s-length transaction with a similarly situated Person not an Affiliate, and (3) the prohibitions in subparts (a) and (d) of this Section 6.15 on transactions with Affiliates are modified as follows: (A) the prohibitions do not apply insofar as such Investment or Guarantee, as the case may be, exists on the Closing Date, and (B) notwithstanding such prohibitions, (i) the Borrower may Guarantee or assume any obligations of a Subsidiary (provided that (I)

Fifth Amendment to Credit Agreement — Page 2

insofar as the obligations being Guaranteed or assumed include any obligation of the Subsidiary to pay Indebtedness, the aggregate outstanding amount of such Guaranteed or assumed Indebtedness does not exceed $25,000,000 at any time, and (II) the Borrower itself could have entered into the transaction or transactions giving rise to the obligations being Guaranteed or assumed without violating any provision of this Agreement), and (ii) the Borrower may make such Investments and Guarantee such obligations if the aggregate outstanding amount of such Investments and such Guaranteed obligations does not at any time exceed 20% of Consolidated Total Assets. In addition, the prohibitions in subpart (a) of this Section 6.15 shall not apply to any Investment permitted under Section 6.13(f) hereof. Similarly the prohibitions in subpart (b) of this Section 6.15 shall not apply to any transfer of assets made in accordance with the provisions of Section 6.10(e) hereof.

      5. Updated Subsidiary Schedule.

(a) Section 5.12. Section 5.12 of the Credit Agreement is deleted and is replaced by the following:

     5.12. Subsidiaries . Each of the Subsidiaries listed on Schedule 5.12 hereto (other than the Foreign Subsidiaries) is a Wholly-Owned Subsidiary of the Borrower, and the Borrower owns and has good title to (free and clear of all Liens), and has the unencumbered right to vote all the ou