To deal with the problem of prison overcrowding, it is important to determine what offense types contribute the most new admissions. Drug offenses appear to be the most significant in prison overcrowding, followed by violent crimes and property offenses. Further, variations in State law lead to different admission rates for specific offenses. In Massachusetts, for example, admissions for certain crimes have fallen while others have risen. National trends toward Truth in Sentencing and Three Strikes legislation may also contribute to prison overcrowding. The diversity of the prison overcrowding problem in Hawaii, Illinois, New York, Oregon, and Washington is described, and prison overcrowding in the United States and Canada is compared. Alternatives to incarceration are noted, including electronic monitoring, intensive probation supervision, community service, house arrest, early release on intensive parole, shock incarceration, and increased good time. 3 footnotes and 1 figure