This report examines the cost offsets and criminal justice outcomes associated with alcohol or drug abuse treatment for adults who receive Supplemental Security Income. Receiving treatment for alcohol or drug abuse was associated with significantly lower costs for medical care, mental health treatment, and nursing home care. The net cost offset, including expenses for chemical dependency treatment and detoxification, equaled $252 per person per month ($3,024 per person per year) for adult SSI clients who received treatment compared to clients who needed treatment but did not get it. Also, the likelihood of arrests or convictions was significantly lower.