42 CFR § 417.533
Part B carrier responsibilities
June 11, 2020
In paying for Part B services furnished to its enrollees by suppliers, the HMO or CMP must—
(a) Determine the eligibility of individuals to receive those services through the HMO or CMP;
(b) Make proper coverage decisions and appropriate payment as authorized under §421.200 of this chapter for the services for which its Medicare enrollees are eligible; and
(c) Carry out any other procedures that CMS may require.
[50 FR 1346, Jan. 10, 1985, as amended at 58 FR 38082, July 15, 1993; 60 FR 46230, Sept. 6, 1995]