The Bayh-Dole Act, passed in 1980, allows recipients of federal research funds the option to retain patents on any inventions they create using those funds. At the same time, the act provides the government with rights intended to ensure that the public benefits from these federal research investments. One of these rights is known as the "march-in" authority, which allows federal agencies to take control of a patent when they have credible information that certain conditions described in the act have been met. Until March 2009, the Bayh-Dole Act required GAO to report periodically on its implementation. To meet that requirement, for select federal agencies, GAO reviewed (1) the policies and procedures used to determine whether march-in authority should be exercised; (2) how the march-in authority has been used; and (3) what barriers and disincentives have been encountered in exercising the march-in authority. GAO selected four agencies for this review that accounted for 89 percent of the federal research funding for fiscal year 2006. These were the Departments of Defense and Energy (DOD and DOE), the National Aeronautics and Space Administration (NASA), and the National Institutes of Health (NIH). GAO is not making any recommendations in this report. DOE, NASA, and NIH provided technical comments on this report that GAO incorporated, as appropriate.