The three models of incarceration that have been prominently used since the middle of the twentieth century are the custodial, rehabilitation, and reintegration models. The early eras focused primarily on the custodial model of incarceration, which was simply locking someone up. In the 1980s and 1990s, it became more and more common to follow the rehabilitation model, which tries to reform and assist inmates, focusing on treatment programs, counseling, and similar services. Since then, the reintegration model has become the most prevalent. The reintegration model attempts to repatriate inmates back into regular society.

A good example of this is in the Scandinavian countries of Sweden and Norway. These countries have an extremely low rate of repeat offenders because they have established a high-quality reintegration program. Reintegration usually focuses on treatment and rehabilitation coupled with education and career training, followed by job placement after release. This gives the inmates an outlet for their time so that they don't get involved in criminal behavior; it also gives them a way to make an income so they don't have to turn to criminal business.