A joint project of the Urban Institute, John Jay College of Criminal Justice, and the Montgomery County (Maryland) Department of Correction and Rehabilitation. This report provides an overview of U.S. jails and the people who cycle through them, examines a variety of ways that jurisdictions can address reentry from jail, profiles 42 jail transition efforts around the country, representing a diversity of approaches in a variety of settings and explores the role of probation in reentry from jail.