This discussion considers the legal standards and policy implications related to each of the aforementioned interfaces. Topics considered in discussing competency to stand trial are the role of the mental health professional, disposition of the incompetent defendant, and proposals for change and development. The section on the insanity defense considers the development of the defense, the sanity evaluation, the successful insanity plea, and proposals for change. The status of State laws pertaining to the disposition of the insanity acquittee is then reviewed, followed by an overview of case law and correctional practices regarding mentally disabled inmates. Criminal justice diversion programs which use the services of mental health professionals are reviewed in the concluding section, particularly programs for drug and alcohol abusers. The chapter concludes that although legislation has sought to improve the lot of the mentally disabled offender, there are often only paper achievements unsupported by significant change. It is argued that what is needed are new treatment programs specifically directed to the needs and conditions of the mentally disabled offender. A list of cases and 29 references are provided.