The American correctional system is the largest in the world by incarceration rate. Jails are locally operated facilities that hold people awaiting trial or serving short sentences, typically less than one year. Prisons are state or federal facilities that hold people serving sentences of one year or more. The distinction matters because jails hold a large population of unconvicted people — individuals who have not been found guilty of any offense but cannot afford bail or were denied pretrial release.

The United States incarceration rate — approximately 500 per 100,000 residents — is among the highest in the world and far exceeds rates in comparable democracies. This rate increased dramatically between the 1970s and the 2000s, driven by changes in sentencing policy, mandatory minimums, and drug enforcement rather than by increases in crime. The National Academies of Sciences concluded in 2014 that the social costs of this level of incarceration are substantial and that its crime-reduction benefits are uncertain.

Institutional conditions affect both the well-being of incarcerated individuals and their prospects upon release. Overcrowding, violence, inadequate medical and mental health care, and limited programming are documented problems in many correctional facilities. The Supreme Court held in Brown v. Plata, 563 U.S. 493 (2011), that California's prison overcrowding constituted cruel and unusual punishment, requiring the state to reduce its prison population.

The 'nothing works' conclusion — associated with Robert Martinson's 1974 review of rehabilitation research — dominated corrections policy for decades. Subsequent research has substantially revised this conclusion. Well-designed rehabilitation programs can reduce recidivism, particularly when they target criminogenic needs — the factors most directly associated with reoffending — and are delivered with fidelity to the program model. The risk-need-responsivity (RNR) model, developed by Andrews and Bonta, provides a framework for matching intervention intensity to offender risk level.

Education programs — including adult basic education, GED preparation, and postsecondary education — have a consistent evidence base for reducing recidivism. A RAND Corporation study found that incarcerated individuals who participated in correctional education programs were 43 percent less likely to return to prison than those who did not. Vocational training programs show similar effects. Despite this evidence, educational programming has been cut in many correctional systems due to budget constraints.

Cognitive-behavioral therapy (CBT) programs address the thinking patterns, attitudes, and beliefs associated with criminal behavior. Programs such as Thinking for a Change, Moral Reconation Therapy, and Reasoning and Rehabilitation have demonstrated reductions in recidivism in multiple evaluations. CBT is among the most consistently supported interventions in corrections research, though effect sizes vary by program quality and population.

Reentry — the transition from incarceration to community life — is a critical period for recidivism risk. Research consistently shows that the period immediately following release is when the risk of reoffending is highest. The barriers to successful reentry are substantial: finding housing, securing employment, maintaining family relationships, accessing treatment, and complying with supervision conditions while managing the collateral consequences of a criminal record.

Collateral consequences of conviction — legal restrictions on employment, housing, voting, professional licensing, public benefits, and immigration status — extend punishment beyond the formal sentence. These consequences are rarely disclosed at sentencing and can persist for decades. Research suggests that they undermine reintegration by limiting access to the stable employment and housing that are associated with desistance from crime.

Community supervision — probation and parole — supervises far more people than are incarcerated. Approximately 3.7 million adults are on probation and 900,000 are on parole in the United States. Supervision violations — including technical violations such as missed appointments or failed drug tests — account for a substantial share of prison admissions. Research suggests that supervision focused on connecting individuals to services and employment, rather than on surveillance and violation detection, produces better outcomes.

Davis, L. M., Bozick, R., Steele, J. L., Saunders, J., & Miles, J. N. V. (2013). Evaluating the Effectiveness of Correctional Education. RAND Corporation. https://www.rand.org/pubs/research_reports/RR266.html

Andrews, D. A., & Bonta, J. (2010). The Psychology of Criminal Conduct (5th ed.). LexisNexis.

Travis, J., Western, B., & Redburn, S. (Eds.). (2014). The Growth of Incarceration in the United States. National Academies Press. https://doi.org/10.17226/18613

Brown v. Plata, 563 U.S. 493 (2011).

Petersilia, J. (2003). When Prisoners Come Home: Parole and Prisoner Reentry. Oxford University Press.

Pew Charitable Trusts. (2011). State of Recidivism: The Revolving Door of America's Prisons. https://www.pewtrusts.org/en/research-and-analysis/reports/2011/04/06/state-of-recidivism-the-revolving-door-of-americas-prisons