Final answer:
The Indian Health Service (IHS) is the federal agency responsible for delivering healthcare services to American Indians and Alaska Natives, falling under the Department of Health and Human Services.
Step-by-step explanation:
The federal agency within the Department of Health and Human Services responsible for providing federal healthcare services to American Indians and Alaska Natives is the Indian Health Service (IHS). The IHS is committed to ensuring that comprehensive, culturally acceptable personal and public health services are available and accessible to American Indian and Alaska Native people. Its foundation rests on the government-to-government relationship between the United States and the sovereign Native nations.
Other healthcare-related agencies include the Veterans Health Administration (VHA), which oversees the services provided to U.S. veterans, the Centers for Medicare & Medicaid Services (CMS), which administers programs like Medicare and Medicaid, and the Food and Drug Administration (FDA), which ensures the safety and efficacy of food, drugs, and other consumer products.