Health and housing impacts of unsheltered homeless encampment resolution programs

The National Institute of Nursing Research (NINR), under the Nursing Research program (CFDA 93.361), awarded $3.41 million to the University of California, Los Angeles (UCLA) on September 5, 2025, for a four-year research project extending through August 31, 2029. This project will generate the first longitudinal empirical evidence examining the health and housing impacts of Encampment Resolution Programs (ERPs)—innovative municipal initiatives utilizing harm reduction and interim housing approaches to address unsheltered homelessness. The research employs a mixed-method design informed by an integrated weathering framework that links environmental stressors associated with unsheltered homelessness to indicators of accelerated aging.

Conducted in Los Angeles County, which hosts the nation's largest homeless population, the project will recruit 400 ERP enrollees to assess whether these programs effectively reduce homelessness and improve health outcomes, or risk creating revolving-door effects that worsen health disparities. Given that hundreds of millions in federal funding have been allocated to ERPs with limited empirical validation, this research will provide critical evidence to inform policy decisions regarding program effectiveness and sustainability in addressing the chronic homelessness crisis affecting people experiencing homelessness (PEH) in the United States.

Abstract

The number of people experiencing homelessness (PEH) in the U.S. Has reached record levels, rising by 13% since 2020. A growing proportion of PEH are experiencing chronic homelessness, illustrating increasing challenges in creating effective pathways to stable housing. The short supply of affordable housing in communities across the U.S. Complicates efforts to scale evidence-based, permanent supportive housing programs to meet the scale of the homelessness crisis. Faced with a growing population of PEH living unsheltered in homeless encampments, many municipalities have been developing new, innovative programs focused on "encampment resolution". Encampment resolution programs (erps) utilize harm reduction policies similar to housing first programs and provide a range of interim housing options. Erps have been endorsed as a way to quickly clear the streets and help reduce health disparities and mortality among PEH as they transition to permanent housing. However, there is also a risk that these programs could create a revolving door, sending PEH back to the streets and worsening health disparities by severing their connections to trusted social and healthcare networks. Hundreds of millions of dollars have been allocated to support erps, yet there is limited empirical evidence examining their effectiveness in reducing homelessness and improving health outcomes. This proposed project will use a mixed method design to provide the first longitudinal evidence on the potential health benefits of erps. The study is informed by an integrated weathering framework that links the environmental stressors associated with unsheltered homelessness to indicators of accelerated aging. Our work is situated in LOS angeles county, CA, which has the nation's largest homeless population, with 75% living unsheltered. We will recruit 400 ERP enrollees into a unique and existing longitudinal study of ~500 unsheltered PEH known as the periodic assessment of trajectories of housing, health and homelessness study, or paths. Using monthly and biannual surveys, we will assess the effects of erps on long-term housing trajectories and a range of health outcomes by comparing the newly recruited ERP cohort to the existing representative comparison cohort from paths. Outcomes will include those related to accelerated aging, its underlying drivers, and the social determinants of health. We will examine the overall effects of the ERP program on health, and disaggregate the results based on whether individuals progress to permanent housing, remain in interim housing, or return to the streets. These findings will be complemented by qualitative interviews with ERP participants about their health and housing experiences. Based on these results, we will develop innovative housing policy guidelines to support policymakers and practitioners in improving the health and well-being of PEH.