BackgroundIn 2011, the Veterans Health Administration (VHA) implemented homeless-tailored primary care medical home models, called the Homeless Patient Aligned Care Teams (HPACT) to improve care for homeless Veterans. The aim of this study was to describe the existing peer-reviewed literature on HPACTs by systematically reviewing studies published since 2011 to date.MethodsWe conducted a systematic review of peer-reviewed studies published from 2011 to June 2019 to evaluate the literature since the inception of the VHA’s Homeless PACT program implementation. We included original research articles evaluating the Homeless PACT and excluded those that did not contain original data.ResultsOf 379 studies screened, 20 studies met our inclusion criteria and were included for analysis. Given wide variability in research designs and outcome measures, a narrative review was conducted. The 20 included studies were categorized into 3 groups: Early HPACT pilot implementations; Association of HPACT clinics with quality and utilization; and Specialized programs within HPACTs. Observational findings suggest reductions in emergency department utilization, improvements in primary care treatment utilization, engagement, and patient experience; but limited rigorous studies exist beyond single site pilots and a few large observational cohort studies.DiscussionThe HPACT model has been successfully implemented in VHA medical centers throughout the country with multiple studies showing increased primary care engagement and improved patient experience; however, further studies are needed about quality, utilization and whether the model can be implemented outside the VHA system.Registration Number/Funding sourcenone