The Medicaid Act requires states to extend Medicaid coverage retroactively–for up to 3 months prior to the date of application. Retroactive coverage is vital because the need often arises because of the sudden onset of a health care crisis—a stroke, an automobile accident, a dangerous communicable disease, a gunshot wound. For the last 2 decades, the federal government has been allowing states to ignore retroactive coverage. This needs to stop. This issue brief explains the history of retroactive coverage and offers recommendations for restoring its critical role.