AMENDMENT NO. 1 TO RECAPITALIZATION AGREEMENT

Exhibit 2.2

AMENDMENT NO. 1 TO

RECAPITALIZATION AGREEMENT

AMENDMENT NO. 1, dated as of March 14, 2005 (this “Amendment”), to the Recapitalization Agreement (the “Agreement”), effective as of December 23, 2004, by and among New Mountain Partners II, L.P., New Mountain Affiliated Investors II, L.P., Allegheny New Mountain Partners, L.P., Deltek Systems, Inc. (“Deltek”), the holders of all outstanding shares of stock of Deltek and Kenneth E. deLaski, in his capacity as Shareholders’ Representative.

WHEREAS, the parties desire to amend the Agreement in certain respects;

WHEREAS, Section 11.8 of the Agreement provides that the Agreement may be amended by an instrument in writing signed by Buyers and the Shareholders’ representative;

NOW THEREFORE, in consideration of the premises and the agreements contained in this Amendment, and intending to be legally bound hereby, the parties hereto agree as follows:

SECTION 1. Amendments.

SECTION 2. Status as a Transaction Document. The parties hereto agree that this Amendment shall be a “Transaction Document” for purposes of the Agreement.

SECTION 3. Effect of Amendment. Except as and to the extent expressly modified by this Amendment, the Agreement shall remain in full force and effect in all respects.

SECTION 4. Counterparts. This Amendment may be executed by facsimile signatures and in any number of counterparts with the same effect as if all signatory parties had signed the same document. All counterparts shall be construed together and shall constitute one and the same instrument.

SECTION 5. Governing Law. This Amendment shall in all respects be governed by, and construed in accordance with, the laws (excluding conflict of laws rules and principles) of the State of New York applicable to agreements made and to be performed entirely within such State, including all matters of construction, validity and performance.

IN WITNESS WHEREOF, each of the undersigned have caused this Amendment to be duly executed and delivered in its name and on its behalf, all as of the day and year first above written.

EXHIBIT B

Buyers’ Investment

List of Buyers

In addition, each Buyer shall receive from Deltek a fully executed copy of the Investor Rights Agreement.

EXHIBIT I

Calculation of Per Share Purchase Price

The price per share to be received by the Shareholders for their Redeemed Shares in connection with the Reorganization Transaction is equal to:

divided by