The United States prison system contains a wide variety of institutions of different security levels, operating under differing forms of regulation. No federal standard exists for surveying prison conditions or providing oversight. While state governments dictate most prison regulations, few external controls are placed on prison operations, according to attorney and prisoner advocate Michele Deitch. Given the lack of oversight, reliable and comprehensive data on prison conditions is rare. The American Correctional Association is working to rectify this by developing and revising standards, and providing accreditation. However, according to the Commission on Safety and Abuse in America's Prisons, as of 2007 less than half of prisons had received accreditation. The Vera Institute of Justice is another independent organization working to promote standards and oversight.
Some of the best information on prison conditions comes from the Commission on Safety and Abuse in America's Prisons, which was formed in 2005 to collect information and testimony about U.S. prisons and jails. The commission was tasked with studying levels of violence, sexual abuse, overcrowding, and other issues relating to prisoner welfare. The commission published its report, "Confronting Confinement", in 2006, including findings and a list of thirty recommendations.
Existing statistics and anecdotal evidence suggest that prison violence and sexual abuse is common. According to Human Rights Watch, 4.5 percent of inmates were sexually assaulted in 2007, or approximately one in 20 prisoners. A report in 2000 stated that 34,000 assaults by prisoners occurred in the preceding year. The Commission on Safety and Abuse in America's Prisons concluded that violence and prison rape are consistently underreported throughout the system, with actual rates possibly five times higher that reported incidents. The commission also received considerable testimony of assaults by correctional officers. Moreover, the commission reported that reporting systems and oversight were inadequate or entirely absent with respect to prison violence.
The commission reported widespread problems of overcrowding and inadequate medical care, Overcrowding contributes to high level of violence. Overcrowding also facilitates the spread of infectious disease. Prisons frequently are not adequately funded to provide appropriate medical care for inmates. Many prisoners have a history of poverty and drug abuse, leading to poor health. Many inmates also suffer from mental health problems. Although prison inmates as a group tend to be less healthy than the average American, prison often operate with a very low ratio of doctors to inmates. In many cases, prison doctors are poorly qualified to deal with the range of health issues faced.