---
kind: "section"
citation: "42 C.F.R. § 421.401"
title: "42"
number: "421.401"
heading: "Definitions."
url: "https://uscodex.org/cfr/42/421.401"
---

# §421.401. Definitions.


For purposes of this subpart—

Appropriate MAC means a MAC that has a contract under section 1874A of the Act to perform a particular Medicare administrative function in relation to:

- (1) A particular individual entitled to benefits under Part A or enrolled under Part B, or both;
- (2) A specific provider of services or supplier; or
- (3) **A class of providers of services or suppliers.** Medicare Administrative Contractor (MAC) means an agency, organization, or other person with a contract under [section 1874A](/cfr/42/1874A.md) of the Act.

## Notes

### Source

Source: 71 FR 68229, Nov. 24, 2006, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 1302 and 1395hh.

### Source

Source: 45 FR 42179, June 23, 1980, unless otherwise noted.