42 CFR §411.8

1. (a)Basic rule. Except as provided in paragraph (b) of this section, Medicare does not pay for services that are paid for directly or indirectly by a government entity.
2. (b)Exceptions. Payment may be made for the following:
   1. (1)Services furnished under a health insurance plan established for employees of the government entity.
   2. (2)Services furnished under a title of the Social Security Act other than title XVIII.
   3. (3)Services furnished in or by a participating general or special hospital that—
      1. (i)Is operated by a State or local government agency; and
      2. (ii)Serves the general community.
   4. (4)Services furnished in a hospital or elsewhere, as a means of controlling infectious diseases or because the individual is medically indigent.
   5. (5)Services furnished by a participating hospital or SNF of the Indian Health Service.
   6. (6)Services furnished by a public or private health facility that—
      1. (i)Is not a Federal provider or other facility operated by a Federal agency;
      2. (ii)Receives U.S. government funds under a Federal program that provides support to facilities that furnish health care services;
      3. (iii)Customarily seeks payment for services not covered under Medicare from all available sources, including private insurance and patients' cash resources; and
      4. (iv)Limits the amounts it collects or seeks to collect from a Medicare Part B beneficiary and others on the beneficiary's behalf to:
         1. (A)Any unmet deductible applied to the charges related to the reasonable costs that the facility incurs in providing the covered services;
         2. (B)Twenty percent of the remainder of those charges;
         3. (C)The charges for noncovered services.
   7. (7)Rural health clinic services that meet the requirements set forth in part 491 of this chapter.