Columbia subject headings:
Health maintenance organizations--United States--Finance.
Hospitals--United States--Cost of operation.
Medical care, Cost of--United States.
Medical economics--United States.
Harvard subject headings:
Health insurance--United States
Hospitals--Economic aspects--United States
Medical economics--United States.
Princeton subject headings:
Health maintenance organizations--United States--Finance.
Hospitals--United States--Cost of operation.
Medical care, Cost of--United States.
Medical economics--United States.