45 C.F.R. § 57.2
As used in the regulations in this part:
Secretary means the Secretary of Health and Human Services.
Department means the Department of Health and Human Services.
Volunteer services are services performed by individuals (hereafter called volunteers) whose services have been offered to the Government and accepted under a formal agreement on a without compensation basis for use in the operation of a health care facility or in the provision of health care.
Health care means services to patients in Department facilities, beneficiaries of the Federal Government, or individuals or groups for whom health services are authorized under the programs of the Department.
Health care facility means a hospital, clinic, health center, or other facility established for the purpose of providing health care.
45 C.F.R. § 57.2