INTRODUCTION: Following the 2014 expansions of Medicaid and private health insurance through the Affordable Care Act, municipal sexually transmitted disease (STD) clinics-which have historically served predominantly uninsured patients-have been threatened with budget cuts nationwide. This study was conducted to evaluate the impact of the insurance expansions on the demand for STD clinic services. METHODS: The proportion of total incident sexually transmitted infections in Baltimore City that were diagnosed at STD clinics was compared between 2013 and 2014, and a multivariate analysis was conducted to determine factors associated with diagnosis at an STD clinic. Analyses were conducted in July 2015. RESULTS: There was no change in the overall proportion of sexually transmitted infection diagnoses made at STD clinics from 2013 to 2014 (relative rate, 1.03; 95% CI=0.95, 1.11). Hispanic ethnicity, black race, male sex, and age >24 years were associated with an increased likelihood of STD clinic utilization (p<0.0001). CONCLUSIONS: Despite the Affordable Care Acts insurance expansion measures, the demand for STD clinics remained stable. These safety net clinics serve patients likely to face barriers to accessing traditional health care and their preservation should remain a priority.