42 CFR § 416.120 - Basis for payment.
The basis for payment depends on where the services are furnished.
(a) Hospital outpatient department. Payment is in accordance with part 419 of this chapter.
(b) [Reserved]
(c) ASC—(1) General rule. Payment is based on a prospectively determined rate. This rate covers the cost of services such as supplies, nursing services, equipment, etc., as specified in § 416.61. The rate does not cover physician services or other medical services covered under part 410 of this chapter (for example, X-ray services or laboratory services) which are not directly related to the performance of the surgical procedures. Those services may be billed separately and paid on a reasonable charge basis.
(2) Single and multiple surgical procedures.
(i) If one covered surgical procedure is furnished to a beneficiary in an operative session, payment is based on the prospectively determined rate for that procedure.
(ii) If more than one surgical procedure is furnished in a single operative session, payment is based on—
(A) The full rate for the procedure with the highest prospectively determined rate; and
(B) One half of the prospectively determined rate for each of the other procedures.
(3) Deductibles and coinsurance. Part B deductible and coinsurance amounts apply as specified in § 410.152 (a) and (i) of this chapter.