Los Angeles County Homelessness Prevention Unit (HPU) Predictive Analytics

Overview

The Los Angeles County Homelessness Prevention Unit (HPU) is a predictive-analytics-assisted homelessness prevention programme operating out of the Housing for Health division of the Los Angeles County Department of Health Services, in close collaboration with the LA County Chief Information Office and the Department of Mental Health. Launched in 2021, the HPU uses linked administrative data to identify people at heightened risk of first-time homelessness or returns to homelessness and then proactively offers support before shelter entry or street homelessness occurs.

The predictive model that powers the HPU was developed by the California Policy Lab (CPL) at UCLA. The model uses approximately 580 variables drawn from integrated administrative data across multiple county agencies, including the Department of Public Social Services, the Department of Mental Health, and the Department of Health Services. These variables include factors such as enrolment in health services, use of public benefits, emergency room visits, arrests, interactions with probation, and prior contacts with homeless services. People on the resulting high-risk list experience homelessness at a rate nearly 3.5 times higher than the broader eligible population.

Once the model identifies high-risk individuals, the HPU conducts proactive outreach through phone calls, mailed letters, and emails rather than waiting for people to request assistance. Case managers carry small caseloads and provide several months of personalised case management. Services include healthcare referrals, job training, mental health treatment, and practical support such as household items or technology needed to stabilise housing and employment. The intervention is therefore framed as preventative support allocation rather than automated denial, sanction, or exclusion.

The HPU pilot phase ran from May 2022 to February 2023. A California Policy Lab report found that participants in the HPU programme were 71 percent less likely to enter a homeless shelter or have contact with street outreach teams within 18 months than similar high-risk individuals who did not enrol. Participants also experienced lower rates of mental health crisis stabilisation events and criminal justice involvement. As of the most recent reporting, the HPU has served 1,498 people, and 86 percent of participants retained their housing upon completion of the programme. The enrolment rate rose from 21 percent to 35 percent after operational improvements including a dedicated outreach team and a standardised case review and discharge process. A formal randomised controlled trial evaluation is underway, with results anticipated in 2027. The integrated administrative data environment that supports the predictive model is governed by Los Angeles County data-sharing agreements and privacy controls that regulate how information flows between participating agencies.

The California Policy Lab also conducted a fairness evaluation of the predictive model, assessing whether it systematically excluded individuals from particular racial, ethnic, or gender groups. That analysis found no evidence of systematic exclusion, with similar false negative rates across groups and no statistically significant differences in performance across race, ethnicity, and gender.

The programme operates within a human-in-the-loop oversight model. Case managers review and validate AI-generated risk flags before outreach or referral actions are taken, and model outputs serve as decision support rather than automated determinations. The decision criticality is high because model outputs can influence access to prevention services and housing support. The HPU has also undergone fairness auditing and uses an integrated administrative data environment governed by county data-sharing and privacy controls.

Classification

Programme Details

The LA County Homelessness Prevention Unit (HPU), operated by the Department of Health Services Housing for Health division, uses a predictive model developed by the California Policy Lab at UCLA to identify and proactively reach individuals at highest risk of homelessness.

Implementation Details

Risk & Oversight

Deployment & Outcomes

Sources

1. SRC-001-USA-001 California Policy Lab (2024) The Homelessness Prevention Unit: A Proactive Approach to Preventing Homelessness. Los Angeles: CPL. Available at: https://capolicylab.org/wp-content/uploads/2024/12/Homelessness-Prevention-Unit-Report.pdf (Accessed: 31 October 2025).
   https://capolicylab.org/wp-content/uploads/2024/12/Homelessness-Prevention-Unit-Report.pdf
2. SRC-008-USA-001 California Policy Lab (2024) 'The Homelessness Prevention Unit: A Proactive Approach to Preventing Homelessness in Los Angeles County', capolicylab.org. Available at: https://capolicylab.org/the-homelessness-prevention-unit-a-proactive-approach-to-preventing-homelessness-in-los-angeles-county/ (Accessed: 27 March 2026).
   https://capolicylab.org/the-homelessness-prevention-unit-a-proactive-approach-to-preventing-homelessness-in-los-angeles-county/
3. SRC-006-USA-001 California Policy Lab (2025) 'Early Outcomes from the Los Angeles County Homelessness Prevention Unit', California Policy Lab. Available at: https://capolicylab.org/early-outcomes-from-the-los-angeles-county-homelessness-prevention-unit/ (Accessed: 24 March 2026).
   https://capolicylab.org/early-outcomes-from-the-los-angeles-county-homelessness-prevention-unit/
4. SRC-002-USA-001 County of Los Angeles (2025) 'New report: Early signs of success from LA County's Homelessness Prevention Pilot', County of Los Angeles, 10 July. Available at: https://lacounty.gov/2025/07/10/new-report-early-signs-of-success-from-la-countys-homelessness-prevention-pilot/ (Accessed: 31 October 2025).
   https://lacounty.gov/2025/07/10/new-report-early-signs-of-success-from-la-countys-homelessness-prevention-pilot/
5. SRC-004-USA-001 NYC CIDI (2023) Homeless Prevention: At-Risk Students in NYC Schools. NYC.gov. Available at: https://www.nyc.gov/assets/cidi/downloads/pdfs/CIDI-Report-Homeless-Prevention-At-Risk-Students-in-NYC-Schools.pdf (Accessed: 31 October 2025).
   https://www.nyc.gov/assets/cidi/downloads/pdfs/CIDI-Report-Homeless-Prevention-At-Risk-Students-in-NYC-Schools.pdf
6. SRC-003-USA-001 NYC Center for Innovation through Data Intelligence (CIDI) (n.d.) 'Predicting Homeless Shelter Entry', NYC.gov. Available at: https://www.nyc.gov/site/cidi/projects/predicting-homeless-shelter-entry.page (Accessed: 24 March 2026).
   https://www.nyc.gov/site/cidi/projects/predicting-homeless-shelter-entry.page
7. SRC-005-USA-001 StateScoop (2025) 'LA County's new predictive model shows early success in homelessness prevention unit', StateScoop. Available at: https://statescoop.com/la-county-ai-predictive-model-reducing-homelessness/ (Accessed: 24 March 2026).
   https://statescoop.com/la-county-ai-predictive-model-reducing-homelessness/
8. SRC-007-USA-001 UCLA Newsroom (2025) 'Homelessness Prevention Unit participants 71% less likely to enter a shelter, California Policy Lab at UCLA finds', UCLA Newsroom. Available at: https://newsroom.ucla.edu/stories/homeless-prevention-unit-helps-keep-people-off-streets-california-policy-lab-at-ucla (Accessed: 24 March 2026).
   https://newsroom.ucla.edu/stories/homeless-prevention-unit-helps-keep-people-off-streets-california-policy-lab-at-ucla