Safety net providers such as community health centers and family planning clinics have served a significant role in the provision of primary care and reproductive health care services to low-income and uninsured people, particularly women. The Affordable Care Act (ACA) has a provision aimed at assuring that newly-insured individuals, as well as those without coverage, can continue seeing their trusted safety net providers, also called Essential Community Providers (ECPs). This brief reviews the definition of ECPs, examines the federal and state rules that govern the extent to which plans must include these providers in their networks, identifies the variation from state to state, and discusses the particular importance of these rules and providers for women’s access to care.