Improving patient retention in HIV care and use of antiretroviral therapy (ART) are key steps to improving the HIV care continuum in the US. However, contemporary quantitative data on barriers to care and treatment from population-based samples of persons poorly engaged in care are sparse. We analyzed the prevalence of barriers to clinic visits, ART initiation, and ART continuation reported by 247 participants in a public health HIV care relinkage program in King County, WA. We identified participants using HIV surveillance data (N=188) and referrals from HIV/STD clinics and partner services (N=59). Participants most commonly reported insurance (50%), practical (26-34%), and financial (30%) barriers to care, despite residing in a state with essentially universal access to HIV care. Perceived lack of need for medical care was uncommon (<20%), but many participants (58%) endorsed a perceived lack of need for medication as a reason for not initiating ART. Depression and substance abuse were both highly prevalent (69% and 54%, respectively), and methamphetamine was the most commonly abused substance. Barriers to HIV care and treatment may be amenable to intervention by health department outreach in coordination with existing HIV medical and support services.