Background: More than 1 million Americans receive primary care from federal homeless health care programs yearly. Vulnerabilities that can make care challenging include pain, addiction, psychological distress, and a lack of shelter. Research on the effectiveness of tailoring services for this population is limited. Objective: The aim was to examine whether homeless-tailored primary care programs offer a superior patient experience compared with nontailored (“mainstream”) programs overall, and for highly vulnerable patients. Research Design: National patient survey comparing 26 US Department of Veterans Affairs (VA) Medical Centers' homeless-tailored primary care (“H-PACT”s) to mainstream primary care (“mainstream PACT”s) at the same locations. Participants: A total of 5766 homeless-experienced veterans. Measures: Primary care experience on 4 scales: Patient-Clinician Relationship, Cooperation, Accessibility/Coordination, and Homeless-Specific Needs. Mean scores (range: 1-4) were calculated and dichotomized as unfavorable versus not. We counted key vulnerabilities (chronic pain, unsheltered homelessness, severe psychological distress, and history of overdose, 0-4), and categorized homeless-experienced veterans as having fewer (≤ 1) and more (≥ 2) vulnerabilities. Results: H-PACTs outscored mainstream PACTs on all scales (all P < 0.001). Unfavorable care experiences were more common in mainstream PACTs compared with H-PACTs, with adjusted risk differences of 11.9% (95% CI = 6.3-17.4), 12.6% (6.2-19.1), 11.7% (6.0-17.3), and 12.6% (6.2-19.1) for Relationship, Cooperation, Access/Coordination, and Homeless-Specific Needs, respectively. For the Relationship and Cooperation scales, H-PACTs were associated with a greater reduction in unfavorable experience for patients with ≥ 2 vulnerabilities versus ≤ 1 (interaction P < 0.0001). Conclusions: Organizations that offer primary care for persons experiencing homelessness can improve the primary care experience by tailoring the design and delivery of services.