Results indicate that 23.1 percent or about one-fourth of the study population had been incarcerated in a New York State prison or a New York City jail within the previous 2 years. Regardless of noted study limitations, the findings indicate that incarceration affects a substantial minority of the single adult sheltered population and that criminal justice issues, whether recognized or not, figure prominently among the homeless population. Jail and prison releases were each associated with different shelter stay patterns, and each type of incarceration calls for a different intervention approach. Prior studies assume there are increased rates of incarceration among the homeless population. Even though research has outlined explanations for this relationship, the empirical dimensions have been left behind. This study addressed this gap as it examined incarceration histories of persons staying in the public, single adult shelter system in New York City and the associations between incarceration histories and shelter use patterns. Tables, notes, and references