On Oct. 1, 2009, the Fed. Aviation Admin. (FAA) entered into a 3-year collective bargaining agreement (CBA) with the Nat. Air Traffic Controllers Assoc. (NATCA). This agreement is the first successfully negotiated CBA since a 5-year agreement ratified with the union in 1998. The 1998 agreement was the first one between FAA and NATCA that included pay and benefits; however, it far exceeded FAA's initial $200 million cost estimate, eventually requiring more than $1 billion in additional funds. The 2009 CBA reinstates numerous provisions of the 1998 agreement. FAA estimates that the 2009 agreement will cost $669 million more than extending the controller work rules that were in place prior to implementing the new agreement. The objectives of this audit report were to (1) evaluate the accuracy and completeness of FAA's cost estimate of the new CBA, (2) identify contract provisions that could escalate the cost, and (3) determine if FAA has sufficient controls in place to prevent such escalations. Figures. This is a print on demand report.