This congressional testimony summarizes research on the utility of halfway houses in facilitating the successful reentry of former prisoners, emphasizing that not all halfway houses are effective in preventing recidivism. Halfway houses that work have qualified staff who use such evidence-based practices as needs assessments and tailored, wraparound services. Halfway houses are most effective for medium- and high-risk prisoners. However, they can actually be detrimental for low-risk prisoners, who would fair better by simply returning directly to their families and communities. This research suggests that the District of Columbia's halfway houses should be reserved for higher-risk returning prisoners.