Maricopa County Jail Capacity Overview
The Maricopa County Sheriff's Office runs the fourth largest jail system in the nation. MCSO actively manages five jail facilities plus the Intake, Transfer and Release center. A seventh site, the 512 Facility, was built in 2020 but is not fully operational and serves as intake overflow. The county uses two campuses: the Downtown Phoenix Campus and the Durango Campus. The 2024 Public Safety Services and Funding report provides facility-by-facility capacity numbers and 2023 average daily population. The full breakdown comes straight from that report, available at the Public Safety Services and Funding report.
Each facility houses a set group. Lower Buckeye is the largest detention site in Arizona at about 670,237 square feet. Estrella holds the county's female population. The 4th Avenue Jail, Watkins, and Towers hold male inmates. ITR books every arrestee before assignment.
| Facility | Rated Capacity | 2023 Average Daily Population |
|---|---|---|
| Lower Buckeye Jail | 2,430 | 1,995 |
| 4th Avenue Jail | 2,064 | 1,564 |
| Estrella Jail | 1,680 | 991 |
| Watkins Jail | 1,600 | 1,355 |
| Towers Jail | 720 | 667 |
| Intake, Transfer, and Release | 573 | 163 |
| 512 Facility | 512 | Not fully operational |
The Jail System Master Plan Refresh from 2024 uses a different number called the 2024 Current Recommended Capacity. It sets total recommended capacity at 7,060 beds by bed type. The Public Safety report adds physical bed counts that sum higher. Design capacity, recommended capacity, and the Hart and Graves court population goals all measure different things. Source documents must be read together. The master plan can be read at the 2024 Maricopa County Jail System Master Plan.
To put a face on the source, the master plan front page is shown below. It comes from the county archive center.
The cover and table of contents are pulled from the 2024 Jail System Master Plan Refresh.
The master plan lays out a 15-year construction, renovation, and repurposing roadmap with a rough cost range of $1.6 billion to $2.0 billion.
Note: Maricopa County covers 9,224 square miles with a 2020 census count of 4,420,568 people and a county estimate near 4,757,600 by end of 2024.
Average Daily Population
The average daily population, or ADP, is the mean number of people in custody on a given day. The Public Safety report states the 2023 ADP for Maricopa County jails was 6,780. That count includes both pretrial holds and sentenced inmates. The figure dropped 11% from a 2019 ADP of 7,648. Pretrial and sentenced ADPs held stable across the last three years of the report.
Pretrial ADP averaged about 5,250 in recent years. Sentenced ADP averaged about 1,485. Together they form the daily count. The pretrial share is much larger than the sentenced share. That split shapes how the jail uses space and how the courts move cases. Pretrial holds are tied to charges, not convictions.
MCSO booked 81,677 people in 2023 and released 81,739 people. The booking number fell hard during the COVID-19 period and has climbed back without reaching 2019 levels. Bookings stood 14% below the 2019 total by the end of 2023. The booking volume drives most ADP changes.
Demographic Breakdown
The Public Safety Services and Funding report gives a gender split for the jail. The breakdown has stayed steady for years. The same report states that around 85% of the daily population is male and 15% is female. That ratio drove the layout of the jail campuses. Estrella was built in 1991 as the dedicated female site. Five tower units and ten dormitories hold female inmates there.
| Group | Percent of Daily Population |
|---|---|
| Male | ~85% |
| Female | ~15% |
The county publishes no further race or age table in the 2024 report at a level that holds up as official data. Race and age breakdowns may appear in the live MCSO inmate roster, which can be checked at Maricopa County inmate records. Live counts shift each day. For a single point-in-time view, the roster is the best source. For trends, the Public Safety report stays the right tool.
The cover of that report is shown below, since the gender data and ADP totals all come from it.
The summary is hosted on the county document center at the official Public Safety Services and Funding report.
The same report drives the figures in the rest of this section and the next two sections on case status and charge type.
Pretrial vs Sentenced Population
Most people in the Maricopa County jail are not serving a sentence. They are held pretrial. Pretrial means a person has been charged but the court has not yet found them guilty. Sentenced means a person has a court order to serve jail time. The split between these two groups is the most-watched number in jail policy.
Using the recent ADP averages from the Public Safety report, pretrial holds account for the larger share. The table below gives the rough share each group holds of the average daily population.
| Status | Average Share of ADP |
|---|---|
| Pretrial | ~78% |
| Sentenced | ~22% |
Length of stay also differs between the two groups. The Public Safety report states that the sentenced inmate average length of stay dropped 29% from 146 days in 2019 to 71 days in 2023. The pretrial average length of stay rose 35% from 20 days in 2019 to 32 days in 2023. Sentenced cases now move faster. Pretrial cases now sit longer. That shift puts more weight on pretrial bed needs.
Note: Pretrial detention does not mean guilt; many pretrial inmates are later released, dismissed, or sentenced to time served on conviction.
Misdemeanor vs Felony Population
The Public Safety report does not list a clean misdemeanor versus felony split at a level fit for a public table. The official county summary breaks the jail population by gender and by case status, not by class of charge. Most jail holds tied to Superior Court cases involve felony counts, since Superior Court handles felony matters in Arizona. Misdemeanor holds tied to Justice Courts or City of Phoenix Municipal Court make up a smaller share.
Booking origin helps fill the gap. The report tracks bookings by the agency that brought a person in. Phoenix Police Department brought in 31,266 people in 2023. Other jurisdictions, which includes city police across the county, brought in 36,043 people. MCSO brought in 4,540 people. Federal agencies brought in 2,875 people. State of Arizona DPS brought in 117 people. Self-surrenders accounted for 6,836 bookings.
Some of those bookings clear within hours through release on own recognizance, citation, or bond. Others lead to full custody. The mix of felony and misdemeanor holds shifts day to day. For charge-level data on a single person, the live jail roster shows current charges on each booking.
Mental Health and Medical Population
Correctional Health Services, called CHS, runs jail medical and mental health care inside MCSO facilities. The Public Safety report states that all arrestees receive a health screening at ITR. CHS then does a full health assessment within 14 days under NCCHC standards. Estrella Jail and Lower Buckeye Jail both house health units for inmates who need ongoing medical care.
The report does not publish a single percent for the mental health caseload in the jail at a level fit for a public table. National research from the Bureau of Justice Statistics shows roughly 44% of local jail inmates have a recent mental health concern. The Maricopa County share has not been broken out in the same 2024 document. The Hart v. Hill and Graves v. Penzone lawsuits set the stage for the county's medical care work. The report notes that lawsuit ended in 2019 but the conditions still drive jail medical practice.
The Custody Bureau runs more than mental health screening. It runs PREA review, a Custody Bureau Hearing Unit, food services through a 170,000 square foot food factory, and an education program that gives inmates access to over 2,400 courses on issued tablets at no cost. Public sources for these services link from the Maricopa County Sheriff's Office site.
National and State Context
The Bureau of Justice Statistics, or BJS, tracks local jail counts each year. The most recent national BJS jail figures put the local jail incarceration rate at roughly 198 per 100,000 U.S. residents. Arizona sits above the national average on most measures. Maricopa County, with a 2023 ADP of 6,780 and a 2024 county estimate near 4,757,600 people, runs a rate near the national mid-range when scaled to its size. The numbers below mark which figures are county-specific and which are wider context.
| Level | Source / Scope |
|---|---|
| Maricopa County 2023 ADP | 6,780 in custody on an average day (county-specific, PSF report) |
| Maricopa County 2023 bookings | 81,677 bookings (county-specific, PSF report) |
| Arizona state context | State and BJS data show Arizona above the U.S. mid-range on jail rate |
| National rate | Roughly 198 per 100,000 U.S. residents (BJS, national context) |
The state figure and national rate are not Maricopa County numbers. They sit in the table only as a frame for the county data. The official source for jail data nationwide is the BJS Annual Survey of Jails. For state context, the Arizona Department of Corrections, Rehabilitation, and Reentry tracks state prison data, which is a separate count from county jail data.
Population Trends Over Time
Booking volume tells most of the trend story. The Public Safety report tracks bookings by origin and year from 2019 through 2023. The table marks the COVID-19 dip and the slow rise back.
| Booking Source | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|
| Phoenix Police | 38,010 | 31,059 | 31,134 | 29,367 | 31,266 |
| MCSO | 5,449 | 3,163 | 3,772 | 4,210 | 4,540 |
| Federal Agencies | 6,194 | 4,287 | 4,581 | 3,983 | 2,875 |
| Arizona DPS | 240 | 150 | 128 | 93 | 117 |
| Other Jurisdictions | 42,860 | 25,278 | 29,183 | 33,869 | 36,043 |
| Self-Surrenders | 1,784 | 3,518 | 7,144 | 7,627 | 6,836 |
| Total | 94,537 | 67,455 | 75,942 | 79,149 | 81,677 |
Bookings fell sharply in 2020 during the pandemic. They have climbed each year since. Self-surrenders nearly quadrupled from 2019 to 2022 before easing in 2023. Federal bookings dropped by more than half over the five-year span. ADP fell 11% over the same window, even as bookings climbed back. Faster sentenced case clearance helped pull the ADP down while pretrial stays grew longer.
Looking ahead, the Jail Master Plan projects total recommended capacity must climb from 7,060 beds in 2024 to 10,721 beds by 2039. That works out to a projected shortage of 3,661 beds without new construction. Male pretrial beds drive most of the projected gap. The plan ties the projection to county growth from 4.4 million people in 2020 to a higher count by 2039.
Where the Data Comes From
The Maricopa County Sheriff's Office is the lead source for jail population data. The agency operates the jail system and is the main booking agency for the county. The MCSO public site is found at the Maricopa County Sheriff's Office. The site lists facility addresses, phone numbers, and inmate lookup tools. Live counts can change hour by hour.
For trend data and ADP, the official documents are the 2024 Public Safety Services and Funding report and the 2024 Jail System Master Plan Refresh. Both are county documents. They cite MCSO source data and the Jail Information Management System. For national context, the U.S. Department of Justice Bureau of Justice Statistics runs the Annual Survey of Jails. The Vera Institute of Justice also tracks county jail counts in its Incarceration Trends data.
The MCSO landing page is shown below for source confirmation.
It is published at the official MCSO website.
The agency footer lists 550 West Jackson, Phoenix, Arizona 85003 and a phone of 602-876-1000 for the main MCSO line.
Note: Use Maricopa County source documents for local figures; use BJS and Vera Institute data for state and national comparison, never the other way around.