The primary healthcare agency of the federal government that deals with health access issues. Its role is to make essential primary care service available to poor, uninsured and geographically underserved populations. HRSA is a division of the U.S. Department of Health and Human Services (HHS). The Division of Transplantation (DoT) is a component of HRSA's Healthcare Systems Bureau (HSB). HRSA provides funding for the OPTN contract.