By the 1980's, corrections did not have a technology for changing behavior which was accepted either within the corrections field, by other criminal justice professionals, or the general public. Yet, sentencing revisions, parole abolition, improved efficiency and expanded capacity by other criminal justice agencies, a postwar baby boom, and undoubtedly other socioeconomic forces had coalesced to produce prison overcrowding. Not only is the space per inmate too little by contemporary correctional standards, but it is also substandard in providing staff safety, prisoner security, and the capacity to minimize idleness. Three generic approaches to eliminating prison overcrowding are to reduce the number who go to prison; reduce the time they stay, including the expanded use of release mechanisms; and increase the capacity of the corrections system. Steps that can be taken by a legislature to reduce prison overcrowding include the decriminalization and reclassification of offenses, the expansion of corrections placement options, the revision of sentencing codes, the setting of facility standards and capacities, and the funding of new construction. Corrections can build new secure facilities and community centers, broaden furlough policy, increase nonsecure placements, revise 'good time' procedures, and establish phased reentry programs. The judiciary can develop sentencing guidelines, use shorter sentences, develop alternative sanctions, refuse substandard facilities, and use specialized offender assessment. Prosecutors can recommend alternative sentences and emphasize financial penalties instead of imprisonment, and citizens and private agencies can advocate and operate alternatives to imprisonment. Seven footnotes are listed.