A total of 845 State agency personnel, participants at a workshop on mental health in jails, jail personnel, professional association representatives, and representatives of related agencies and organizations were contacted by letter and through personal and telephone interviews, and 193 programs descriptions were requested. These requests resulted in the identification of 81 programs, 20 of which were visited on sight and 6 of which were selected as model programs. The programs identified included Marengo County, Ala., Los Angeles and Napa Counties, Calif.; Monmouth County, N.J., Cuyahoga County, Ohio, and Whitman County, Wash. In addition, the State of Michigan was selected as a model of a statewide approach to the problem. The process of identifying the models and the models themselves suggest that research should concentrate on a common definition of jail mental health services, on program typology and treatment strategies, jail characteristics influencing the type of delivery model adopted, and the effect of mental health programs on security and jail management. Responses indicated that combined programs may be more effective than internal ones in some jails. Inmate characteristics and program budget have an undetermined effect on program development. The use of alternative placements affected the distribution of mentally ill inmates in the jail, as the jail and mental hospital populations appeared to vary inversely with one another. Tabular data, charts, extensive program descriptions and documentation, a bibliography consisting of about 130 items, and 13 references are provided.