(1) Background: Homelessness contributes to both needs for care and barriers to access. This study aimed to explore the utilization of medical or dental services using Andersen's model for a vulnerable population of homeless in South Korea. (2) Methods: The data were applied from the first national survey for homeless people in South Korea, 2016. Totally 2032 persons participated in the interview survey. This study team requested the raw data through the public portal and analyzed them. (3) Results: The participants who were homeless for more than ten years, staying in small rooming house or shelter, non-employed, earning less than 500,000 won per month, and having a medical condition showed a significantly higher chance of using Medicaid. The use of outreach programs had a significant relationship with gender, duration of homelessness, and monthly income. Among dental patients, the homeless who did not consume alcohol, stayed in a shelter, and were employed had higher chances of using dental service. (4) Conclusions: Medicaid service was strongly related to enabling factors but outreach programs with predisposing factors. Dental service showed strong relationships with the enabling domain, but the pattern was opposite: the jobless had less chance to avail it. The policymakers need to consider these domains of service utilization to provide equitable access to healthcare services.
Keywords: homeless; medicaid program; outreach program; utilization of health service.