The private sector has become involved in corrections in many ways: by employing inmates, by providing programs and services, by managing areas of prison operations, and by applying techniques and technology. Questionnaires were sent to correctional administrators, researchers, scholars and private sector providers in the State, District of Columbia, and federal prison systems. The results found that the degree of private sector involvement was widespread: 52 of the 54 agencies responding to the questionnaire reported at least one private sector contract. Thirty-seven adult and 29 juvenile agencies in 39 State jurisdictions and the District of Columbia use 32 types of private sector services or programs. The most frequent uses of the private sector are in the provision of health services, educational and vocational training, aftercare and halfway house programs, and staff training. Two problems found in the use of the more cost-effective private sector providers are monitoring their performance and the poor quality of some services. Suggested guidelines for using private sector services are included. Annotated bibliography.