The Indian Health Service (IHS), part of the Public Health Service (PHS) of the Department of Health and Human Services (HHS), funds health services to about 1.8 million Indians, members of the nation's 562 federally recognized American Indian and Alaska Native (AI/AN) tribes in IHS service delivery areas. Health services are available to eligible residents of reservations, of non-reservation areas of those counties that overlap or abut reservations, and of some urban areas with a significant AI/AN population. Eligible Indians receive free IHS health services regardless of their ability to pay (except in certain urban programs, or when a tribe chooses to charge for services). The federal government considers its provision of these health services to be based on its trust responsibility for Indian tribes, a responsibility derived from federal statutes, treaties, court decisions, executive actions, and the Constitution (which assigns authority over Indian relations to Congress). Congress, however, has only a moral obligation, not a legal one, to provide Indian health care. The Supreme Court has rejected the idea (absent congressional statement to the contrary) that IHS is under an obligation to provide any specific health program to Indians. This report provides an overview of the Indian Health Service and how it provides for the health care problems and needs of AI/AN. It also shows IHS appropriations for recent years and discusses its current statutory authorities and legislative issues, including the reauthorization of appropriations in the Indian Health Care Improvement Act (IHCIA) and several other policy issues. The federal government's delivery of health services to Indians, and funding of tribal and urban Indian health programs, has developed over more than a century. ( Appendix provides a brief history of the Indian Health Service.) Currently, the IHS health care delivery system, a largely rural system, is organized into regional area offices and, within each region, local service units. As of 2006, there were 12 regional area offices and 161 local service units. The IHS system serves federal reservations, Indian communities in Oklahoma and California, and Indian, Eskimo (Inuit and Yupik), and Aleut communities in Alaska. Service units, as geographic entities, may be made up of both whole counties and parts of counties. All counties in the national IHS service area are covered by one or more service units. The map in Figure 1 shows the counties served by IHS-funded programs (as of 2001), including both IHS service areas and IHS-funded urban projects. As a whole, the IHS national service area roughly matches the distribution of federal Indian reservations and communities, although in five states (Alaska, Arizona, Nevada, Oklahoma, and South Carolina) every county is served by the IHS. The IHS provides an array of medical services, including inpatient, ambulatory, emergency, dental, public health nursing, and preventive health care. The IHS does not have a defined medical benefit package that excludes or includes specific conditions or types of health care. Besides providing general clinical health services, the IHS also focuses on such special Indian health problems as maternal and child health, fetal alcohol syndrome, diabetes, hepatitis B, alcoholism, and mental health. The IHS provides these services directly, and through tribes, tribal organizations, and urban Indian organizations. In addition, both the IHS and tribes may contract for health services from private providers. As noted, IHS-funded health care is provided in facilities administered through regional offices and service units. Service units and specific health facilities (but not IHS regional offices) may be managed either by the IHS directly, or by Indian tribes and tribal organizations and consortia through self-determination contracts and self-governance compacts negotiated with the IHS under the authority of the Indian Self-Determination and Education Assistance Act (ISDEAA). Tribes and tribal organizations have taken over from IHS the responsibility for operating many service units and health facilities. (The ISDEAA is discussed at greater length below, under "Statutory Authority.") Currently, 100 of the 161 service units (62%) are operated by tribes under ISDEAA, as are 522 of the 646 IHS-funded health facilities (81%) (see Table 1 ). In addition to care received from IHS and tribal providers, health services are purchased by IHS and the tribes through contracts with more than 2,000 private providers, if the local facility is unable to provide the needed care. Not all areas of the country are covered by this service. Areas where this IHS-funded contract health care is available are known as "contract health service delivery areas" (CHSDAs), and are the same as the IHS service areas shown in Figure 1 . CHS providers may not bill Indians for CHS services authorized by the IHS. Although most IHS facilities are located on or near reservations, IHS also funds, with approximately 1% of its budget, 34 urban Indian health projects (UIHPs), with operations at 41 locations. UIHPs are funded by IHS with grants and contracts. In 2000 UIHPs served an estimated 669,970 urban Indians living in IHS's urban service areas. UIHPs also receive funding from other sources, including state, private, and non-IHS federal programs, and from patient fees. Figure 1 displays the areas served by urban Indian health projects. Some urban projects are inside CHSDAs and some are not. The IHS funds the construction, equipping, and maintenance of hospitals, health centers, clinics, and other health care delivery facilities, both those operated by the IHS and those operated by tribes. Tribes may handle these activities under self-determination contracts or self-governance compacts. Since 1960, under the authority of the Indian Sanitation Facilities Act, the IHS has also funded the construction of water supply and sewage facilities and solid waste disposal systems, and has provided technical assistance for the operation and maintenance of such facilities. According to the IHS in 2005, about 12% of AI/AN homes lack safe drinking water supplies and adequate waste disposal facilities, compared to about 1% of all U.S. homes. Because of improved access to sanitation facilities, there has been about an 80% reduction in gastrointestinal disease among AI/AN since 1973, according to the IHS. The IHS does not provide the same health care services in each area it serves. Services vary from place to place and from time to time. In general, the services provided to any particular Indian community will depend on financial resources (i.e., appropriations and third party reimbursements) and available personnel and facilities. IHS has stated that its funding does not allow it to provide all the needed care for eligible Indians. As a result, according to Indian health organizations, some services are "rationed," with the most critical care given first. IHS regulations require that, when resources or funds are insufficient, the agency must set priorities for both direct and contract health care based on "relative medical need." In addition, the drugs and medicines available from IHS pharmacies may not include all drugs and medicines needed, although IHS says its pharmacies will stock most drugs that have proven to be cost-effective and beneficial. IHS shortfalls in medical personnel contribute to this unevenness in health care delivery. Where a health professional position is vacant, either the health care may not be available or the facility will have to use CHS funds, which according to IHS raises the costs of the care. In January 2008, the IHS had job vacancy rates of 31% for dentists, 18% for nurses, 17% for physicians, 13% for optometrists, and 11% for pharmacists. In general, persons eligible for IHS services are members of federally recognized tribes. They must also live on or near federal Indian reservations or in traditional Indian communities, or within a county where IHS contract health services are available. Eligible Indians include those of Indian descent belonging to the Indian community who are regarded as Indian by the community in which they live. Eligibility also is indicated by: (1) location within an IHS health service delivery area; (2) residence on tax-exempt land or ownership of property on land for which the federal government has a trust responsibility; (3) active participation in tribal affairs; or (4) meeting other relevant factors in keeping with general Bureau of Indian Affairs (BIA) practices in the jurisdiction for determining eligibility. Urban Indian health programs funded by IHS may serve a wider range of eligible persons, including members of terminated or state-recognized tribes and their children and grandchildren. In addition, eligible persons may also include a non-Indian woman pregnant with an eligible Indian's child. She would be eligible for care during the pregnancy and six weeks following birth, as long as paternity is acknowledged. The IHS also serves non-Indians in specific circumstances particularly when an acute infectious disease is involved. Most IHS services are intended for members of federally recognized tribes. Since federal law does not restrict state recognition of tribes, some states grant recognition to Indian groups that are not recognized by the federal government. Members of such state-recognized tribes are ineligible for most IHS health services, but are eligible for services at IHS-funded urban Indian health projects. For the most part, tribal membership is determined by the tribe. Many tribes require recognized descent from a particular tribal roll for membership. In tracing descent, tribes follow paternal or maternal. bloodlines, or both. Some tribes require minimum percentages of genealogical descent, and others require only proof of descent. For a few tribes, Congress has set membership criteria in statute. The IHS service population (as calculated by IHS) is not evenly distributed throughout Indian country.