In an era in which public postsecondary institutions increasingly face budget constraints, the state residency of students has become an important factor in complex decisions on tuition-setting policies and enrollment management. This report examines the current trends and impact of out-of-state tuition premiums -- defined as the additional amount of tuition and fees for nonresident students -- at public four-year institutions in the U.S. Regional approaches to reducing out-of-state tuition premiums are described, and past research on the effects of tuition premiums is summarized.