Experiments with patented compounds or processes are sometimes necessary for Food and Drug Administration approval of a small-molecule drug, biologic, or medical device. The law exempts certain research and development activities using these patented compounds or processes. The two exemptions are (1) a judicially created exemption developed through case law and (2) an exemption created by the Hatch—Waxman Act (the “safe harbor” pro-vision). This article analyzes the history of these exemptions and how the courts have interpreted their scope and provides future perspectives on protecting research and development activities from liability.