Vera's Substance Use and Mental Health Program (SUMH) partnered with the New York City Department of Correction to design methods for identifying people in the city's jail system who were most in need of services to prepare them for reentry into the community. The result was the creation of the Service Priority Indicator-a simple screening tool for targeting reentry services that uses administrative data held by the jail to identify people who are at greatest risk of being rearrested and returned to jail custody upon release.