Federal regulation requires states to provide three months of retroactive eligibility for Medicaid, if an individual received covered services and would have been eligible at the time the service was provided. As of August 2019, 30 demonstrations in 27 states have been approved to make changes to the retroactive eligibility period as part of Section 1115 demonstration waivers. This issue brief provides an overview of retroactive eligibility policies in states with approved waivers, including the policy goals and the features of the demonstrations. It describes states’ evaluation plans and contains an appendix summarizing features of each approved waiver.