This proposal has two major purposes: 1) to provide enhanced treatment to an underserved and relatively unstudied (but growing) population of homeless mentally ill chemical abusers and 2) to compare outcomes, over a two year follow-up period, of these MICA's randomly assigned to the two major residential treatment modalities in each field. To do this, we have enhanced these modalities by adding 1) psychiatric care and vocational counseling to a therapeutic community and 2) substance abuse and vocational counseling to a community residence. Four hundred men with severe mental illness aggravated by substance abuse and homelessness will be randomly assigned to one of the two enhanced residential programs. We expect 140 dropouts (leavers) and 260 to finish treatment (stayers). The stayers will be followed up for two years after admission to the program and the leavers will be traced and interviewed at exit and again one to two months after they leave. The study proposes to answers the following questions: 1) How do Enhanced Therapeutic Community and Enhanced Community Residence outcomes compare in terms of change in mental status, drug abuse, housing and vocational status; 2) How do dropouts compare with those who complete treatment; 3) How does abstinence effect .psychiatric diagnosis; 4) What is the impact of stigma on homeless mentally ill substance abusers?