In order to better understand what threatens vulnerable populations’ access to primary care, it is important to understand the factors associated with closing safety net clinics. This article examines how a clinic’s financial position, productivity, and community characteristics are associated with its risk of closure. We examine patterns of closures among private-run primary care clinics (PCCs) in California between 2006 and 2012. We use a discrete-time proportional hazard model to assess relative hazard ratios of covariates, and a random-effect hazard model to adjust for unobserved heterogeneity among PCCs. We find that lower net income from patient care, smaller amount of government grants, and lower productivity were associated with significantly higher risk of PCC closure. We also find that federally qualified health centers and nonfederally qualified health centers generally faced the same risk factors of closure. These results underscore the critical role of financial incentives in the long-term viability of safety net clinics.