Correctional officials, courts, and legislatures have concluded, to varying degrees, that inmates must have access to adequate health care. Adequate mental health care involves identifying inmates' individual problems or needs and providing treatment tailored to meet their needs. The mental health care delivery systems of most prisons did not identify all inmates needing help or provide proper care. While federal and state prisons required that new inmates be screened to determine their needs, this was not always adequate to identify mental health problems. The services provided inmates varied among prisons, but, in general, treatment efforts focused on inmates who were dangerous to themselves or others. Shortages of beds and staff limited the ability of most prisons to provide adequate care on either a daily or long-term basis. The Bureau of Prisons and three of the five states visited by GAO tended to treat behavioral disorders only when inmates requested help or when a crisis arose. A lack of standards hampered a Bureau effort to provide treatment programs for drug abusers, and the Bureau gave less attention to programs for alcohol abusers. State programs to treat drug and alcohol abusers reached relatively few inmates. Although limited funds and shortages of qualified staff will likely continue, improved administration could minimize many of the current inadequacies. In addition, better use of the variety of financial and technical assistance programs designed to help states improve the availability of treatment services for prison inmates could assist in bringing about coordinated planning by state criminal justice and health agencies to identify inmates' needs, support development of treatment programs and management, and provide research and training assistance.