In U.S. jails and prisons, 23 and 1 solitary confinement refers to a housing schedule in which a person is locked alone in a cell for 23 hours a day and allowed out for one hour, typically used for a brief shower and solitary recreation in a small enclosed area. An estimated 122,000 people were held in some form of solitary confinement in American prisons and jails as of the most recent national count, making this schedule one of the most common conditions of confinement in the system.
What the Cell and the Hour Out Look Like
Solitary cells are roughly the size of an elevator. Most measure about six feet by nine feet, though some facilities use cells closer to eight by ten. Inside is a steel bunk bolted to the wall, a combined toilet-and-sink unit, and sometimes a small shelf or writing surface. The door is solid steel with a narrow slot at waist height for passing food trays and handcuffs. A small window in the door or wall may let in some light, but many cells have limited or no access to natural daylight.
The one hour out of the cell is not free time in any ordinary sense. People are typically handcuffed through the door slot before being escorted anywhere. Exercise usually takes place alone in a concrete pen sometimes called a “dog run,” which may or may not have a view of the sky. The Federal Bureau of Prisons sets exercise at a minimum of five hours per week, ordinarily in one-hour blocks on different days.1Federal Bureau of Prisons. Special Housing Units Showers are limited; federal detention standards require at least three per week, and most state systems follow a similar schedule.2U.S. Marshals Service. Federal Performance Based Detention Standards Handbook On a given day, the hour out may be the shower or the recreation pen, not both.
The defining feature of this housing is isolation. People in these units have almost no face-to-face contact with other human beings. Conversations, when they happen at all, take place through the door slot or by shouting between cells.
A Day on the 23 and 1 Schedule
Life inside is monotonous by design. Meals arrive through the door slot three times a day on a tray. Some facilities use bag meals with finger foods instead, since utensils can pose a security concern. Eating happens alone, often on the bunk, a few feet from the toilet.
Phone calls, visits, and mail are sharply curtailed. Under federal rules, people in disciplinary segregation lose commissary access and have personal property impounded, keeping only limited reading material and religious items.1Federal Bureau of Prisons. Special Housing Units Educational classes, job assignments, and substance abuse programs are generally unavailable. For people serving months or years in these conditions, the days blur together.
Why People End Up in 23 and 1
Facilities use this housing for several distinct reasons, and the label attached to the placement matters because it affects how long the person stays and what rights they have.
Disciplinary Segregation
This is solitary as punishment. When an incarcerated person is found guilty of violating facility rules at a formal hearing, a hearing officer can impose a stretch in segregation as a sanction. In the federal system, the maximum duration depends on the severity of the offense. The most serious violations, like assaulting staff or possessing a weapon, can result in up to 12 months of disciplinary segregation, with repeat offenses at that severity level carrying up to 18 months. High-severity acts carry a cap of six months, moderate-severity acts up to three months, and low-severity acts generally do not trigger segregation unless the behavior is repeated.3eCFR. 28 CFR 541.3 – Prohibited Acts and Available Sanctions State systems set their own limits, and some allow significantly longer stretches.
Administrative Segregation
Administrative segregation is not technically punishment. It is used when officials decide someone needs to be separated from the general population for security reasons, during an active investigation, or while awaiting transfer. People with gang affiliations or those considered escape risks often land in this category. Unlike disciplinary segregation, administrative segregation often has no fixed end date. A person can be held for years in conditions identical to punitive segregation while being told it is a management decision rather than a sanction.
Protective Custody
Some people are placed in solitary for their own safety. This includes people who have cooperated with law enforcement, those vulnerable to sexual victimization, and anyone whose presence in general population would put them at serious risk. Federal immigration detention standards require that protective custody placements based on sexual abuse vulnerability be used only as a last resort, for no more than 30 days, and only when no alternative housing exists. The person must receive access to programs, visitation, and legal counsel as close to what general population receives as possible.4eCFR. 6 CFR 115.43 – Protective Custody In practice, protective custody often looks and feels identical to punitive solitary. The person being “protected” ends up in the same small cell under the same 23-hour lockdown.
How Long a Stay Can Last
There is no single national limit. The federal caps on disciplinary segregation above apply to Bureau of Prisons facilities, but administrative segregation in the federal system has no statutory maximum. Some people have spent decades in solitary confinement in state prisons.
International standards draw the line much sooner. The United Nations Standard Minimum Rules for the Treatment of Prisoners, known as the Nelson Mandela Rules, define solitary confinement as holding someone in a cell for 22 or more hours a day without meaningful human contact. Anything beyond 15 consecutive days qualifies as “prolonged” solitary confinement, and the Rules explicitly prohibit it alongside indefinite solitary, classifying both as forms of cruel, inhuman, or degrading treatment.5United Nations Office on Drugs and Crime. The United Nations Standard Minimum Rules for the Treatment of Prisoners (Nelson Mandela Rules)
A growing number of states have adopted the 15-day threshold into law. New York’s HALT Act, Colorado’s restrictive housing statute, and Connecticut’s solitary confinement reform all cap continuous isolation at 15 days. As of mid-2022, seven states had enacted provisions specifically addressing solitary confinement, with three enacting comprehensive reforms. Many other states still allow placements lasting months or years.
Who Is Not Supposed to Be Placed in 23 and 1
Federal policy and a growing body of law restrict solitary confinement for certain populations whose vulnerability makes 23-and-1 conditions especially dangerous.
Juveniles are one such group. In 2016, President Obama banned solitary confinement for juveniles in federal prisons and reduced the maximum segregation term for first-time offenders from 365 days to 60 days. The federal system holds relatively few juveniles, but the ban set an important marker, and a majority of states have since enacted some restriction on isolating young people.6The White House (Obama Administration). President Obama – Why We Must Rethink Solitary Confinement
People with serious mental illness are another. Department of Justice policy recommends against placing anyone with serious mental illness in restrictive housing unless a qualified mental health professional confirms the placement is not clinically harmful, the person is not a suicide risk, and the person does not have active psychotic symptoms. BOP policy further requires that any person with serious mental illness be removed from the Special Housing Unit before reaching six months of continuous placement, unless extraordinary security needs exist.7U.S. Department of Justice. Report and Recommendations Concerning the Use of Restrictive Housing8Federal Bureau of Prisons. Special Housing Units
The DOJ has also recommended that women who are pregnant, postpartum, or recovering from a miscarriage or terminated pregnancy should not be placed in restrictive housing.7U.S. Department of Justice. Report and Recommendations Concerning the Use of Restrictive Housing Whether facilities consistently follow any of these policies is a different question, and advocates have documented widespread noncompliance.
What Prolonged Isolation Does to People
The psychological toll is severe and well-documented. A study of people held in Washington State’s solitary units found clinically significant rates of depression and anxiety in about 25% of the population, hallucinations in nearly 10%, and self-harm attempts in 18%. Twenty-two percent had attempted suicide. Eighty percent of the people interviewed described a significant emotional toll, and 73% identified social isolation as a defining hardship.9National Center for Biotechnology Information. Psychological Distress in Solitary Confinement – Symptoms, Severity, and Prevalence
Those numbers track with decades of research finding that prolonged isolation produces anxiety, paranoia, difficulty concentrating, memory loss, hypersensitivity to stimulation, and in some cases full psychotic episodes. People who enter solitary with preexisting mental health conditions tend to deteriorate rapidly. People who enter with no prior diagnosis sometimes develop symptoms that persist long after they leave.
The physical effects are less studied but real. Confinement to a small cell for 23 hours a day means almost no cardiovascular activity and minimal movement. Chronic headaches, joint pain, and deteriorating eyesight from the constant close-range visual environment are commonly reported. The lack of natural light disrupts circadian rhythms, compounding sleep disorders and mood instability. Research on people released from solitary has also found an approximately 15% higher rate of reconviction within three years compared to people who committed similar infractions but were not placed in isolation.
Where Reform Stands
Political momentum to limit or ban solitary confinement has been building for more than a decade. The most ambitious current proposal at the federal level is the End Solitary Confinement Act, introduced in the 119th Congress in July 2025. The bill would prohibit solitary confinement in federal facilities entirely, replacing it with a requirement of at least 14 hours per day of out-of-cell time with congregate interaction. Emergency lockdowns would be capped at four hours per incident and 12 hours in any seven-day period. The bill would also categorically bar involuntary cell confinement for people 25 and younger, 55 and older, pregnant or postpartum individuals, people with any diagnosed mental health condition, and people with disabilities.10Congress.gov. S.2477 – End Solitary Confinement Act As of its introduction, the bill’s status is “introduced” and it faces significant opposition from corrections unions and some law enforcement groups.
At the state level, the landscape is uneven. New York, Colorado, and Connecticut have enacted comprehensive reforms capping continuous solitary at 15 days, aligning with the Nelson Mandela Rules. Several other states have adopted narrower restrictions targeting specific populations like juveniles or people with mental illness. Many states still have no meaningful limits on how long someone can be held in isolation, and the gap between policy on paper and conditions on the ground remains wide even in jurisdictions that have passed reforms.