The proposed demonstration project will test the effectiveness of a new, intensive multiphasic intervention model for chronically homeless veterans with alcohol and/ or drug problems. The proposed Case Managed Residential Care (CMRC) program will provide five days of intensive hospital "detox" followed by a graduated step down therapy featuring intensive case management during the CMRC program and during a six nth aftercare period. It is hypothesized that the CMRC program will reduce the costs associated with the treatment of homeless substance abusers to the VA and to society in general. It is also hypothesized that clients, after participating in CMRC, will demonstrate a decrease in their alcohol and/or drug use, an increase in their residential stability and improvement in their economic/employment status and mental health status. The study will be a three year prospective experiment involving approximately 270 homeless male veterans. The majority of subjects will be Black with an average age of 42-43 and a range of 25-70. All will have DSM III R diagnosis of substance abuse/dependency; and a significant number (70%) will also have co-existing mental disorders. After the five day detox phase, subjects will be randomized into two groups: 1) the experimental group which will enter the CMRC program and 2) the control group which will receive the usual treatment of the current VA substance abuse unit. Structured interviews with subjects will occur at entry into the study, at discharge, six mouths post admission, and 12 months post admission. In the analyses, the two groups will be compared on abstinence, psychiatric, social and vocational functioning and the utilization of medical and mental health services. A cost benefit analysis will determine whether the costs of the experimental intervention are offset by the reduction in the use of other services.