The Health Resources and Services Administration (HRSA) administers the Health Center Program as authorized by section 330 of the Public Health Service (PHS) Act, as amended (42 U.S.C. 254b).  Health centers improve the health of the Nation’s underserved communities and vulnerable populations by ensuring access to comprehensive, culturally competent, quality primary health care services. Health Center Program grants support a variety of community-based and patient-directed public and private nonprofit organizations that serve an increasing number of the Nation’s underserved. Individually, each health center plays an important role in the goal of ensuring access to services, and combined, they have had a critical impact on the health care status of medically underserved and vulnerable populations throughout the United States and its territories.  Targeting the Nation’s neediest populations and geographic areas, the Health Center Program currently funds more than 1,200 health centers that operate more than 8,500 service delivery sites in every state, the District of Columbia, Puerto Rico, the Virgin Islands, and the Pacific Basin.  In 2011, more than 20 million medically underserved and uninsured patients received comprehensive, culturally competent, quality primary health care services through the Health Center Program. This Funding Opportunity Announcement (FOA) solicits applications for the Health Center Program’s Service Area Competition-Additional Area (SAC-AA). The FOA details the eligibility requirements, review criteria, and awarding factors for organizations seeking a grant for operational support of an announced service area under the Health Center Program, including Community Health Center (CHC – section 330(e)), Migrant Health Center (MHC – section 330(g)), Health Care for the Homeless (HCH – section 330(h)), and/or Public Housing Primary Care (PHPC – section 330(i)).  For the purposes of this document, the term “health center” refers to the diverse types of health centers (i.e., CHC, MHC, HCH, and /or PHPC) supported under section 330 of the PHS Act, as amended.