The federal health center program awards grants to support health centers: outpatient primary care facilities that provide care to primarily low-income individuals. The program supports four types of health centers: community health centers, health centers for the homeless, health centers for residents of public housing, and migrant health centers. Health centers are required to provide health care to all individuals regardless of their ability of pay and are required to be located in geographic areas that have few health care providers. These requirements make health centers part of the health safety net – providers that serve the uninsured, the underserved, or those enrolled in Medicaid. This book provides an overview of the federal health center program including it statutory authority, program requirements, and appropriation levels.