Background: In preparation for full Affordable Care Act implementation, California has instituted two healthcare initiatives that provide comprehensive coverage for previously uninsured or underinsured individuals. For many people living with HIV, this has required transition either from the HIV-specific coverage of the Ryan White program to the more comprehensive coverage provided by the county-run Low-Income Health Programs or from Medicaid fee-for-service to Medicaid managed care. Patient advocates have expressed concern that these transitions may present implementation challenges that will need to be addressed if ambitious HIV prevention and treatment goals are to be achieved., Methods: 30 semi-structured, in-depth interviews were conducted between October, 2012, and February, 2013, with policymakers and providers in 10 urban, suburban, and rural California counties. Interview topics included: continuity of patient care, capacity to handle payer source transitions, and preparations for healthcare reform implementation. Study team members reviewed interview transcripts to produce emergent themes, develop a codebook, build inter-rater reliability, and conduct analyses., Results: Respondents supported the goals of the ACA, but reported clinic and policy-level challenges to maintaining patient continuity of care during the payer source transitions. They also identified strategies for addressing these challenges. Areas of focus included: gaps in communication to reach patients and develop partnerships between providers and policymakers, perceived inadequacy in new provider networks for delivering quality HIV care, the potential for clinics to become financially insolvent due to lower reimbursement rates, and increased administrative burdens for clinic staff and patients., Conclusions: California's new healthcare initiatives represent ambitious attempts to expand and improve health coverage for low-income individuals. The state's challenges in maintaining quality care and treatment for people living with HIV experiencing these transitions demonstrate the importance of setting effective policies in anticipation of full ACA implementation in 2014.