Summary: GAO discussed legislation establishing a milestone authorization process to reduce funding uncertainties associated with congressional review of defense acquisition programs. Each military service is required to nominate at least three programs as defense enterprise programs, which Congress then considers for milestone authorization. The legislation's purpose is to enhance program stability through multiyear authorizations and to provide a more efficient management structure for defense acquisition programs. GAO supports the legislation's objectives and believes that, to successfully implement the enterprise program, the Department of Defense (DOD) should carefully select a few stable programs in the early stages of the process for Congress to oversee. The legislation requires that: (1) the program manager prepare a comprehensive baseline of cost, schedule, and technical issues from which to measure program progress; and (2) DOD submit a report whenever a program deviates from the baseline. GAO would continue to review aspects of the selected programs as part of the oversight process. GAO also believes that, to integrate milestone authorizations into a biennial budget, Congress may wish to: (1) withhold approval of any system as an enterprise program until operational test results are available; or (2) provide only tentative approval, pending DOD certification that operational tests show that the system meets performance expectations.