---
kind: "section"
citation: "42 C.F.R. § 407.1"
title: "42"
number: "407.1"
heading: "Basis and scope."
url: "https://uscodex.org/cfr/42/407.1"
---

# §407.1. Basis and scope.

- (a) **Statutory basis.** The supplementary medical insurance (SMI) program is authorized by Part B of title XVIII of the Social Security Act.
  - (1) **Section 1831 of the Act establishes the program.**
  - (2) **Sections 1836 and 1837 set forth the eligibility and enrollment requirements.**
  - (3) [Section 1838](/cfr/42/1838.md) specifies the entitlement periods, which vary depending on the time and method of enrollment and on the basis for termination.
  - (4) [Section 1843](/cfr/42/1843.md) sets forth the requirements for State buy-in agreements under which States may enroll, and pay the SMI premiums for, eligible individuals who are also eligible for cash assistance or Medicaid.
  - (5) **Section 104(b) of the Social Security Amendments of 1965 (Pub.** L. 89-87) specifies the limitations that apply to certain aliens and persons convicted of subversive activities.
  - (6) Sections 1836(b) and 1837(n) of the Act provide for coverage of immunosuppressive drugs as described in section 1861(s)(2)(J) of the Act under Part B beginning on or after January 1, 2023, for eligible individuals whose benefits under Medicare Part A and eligibility to enroll in Part B on the basis of ESRD would otherwise end with the 36th month after the month in which the individual receives a kidney transplant by reason of [section 226A(b)(2)](/cfr/42/226A.md?p=b-2) of the Act.
- (b) **Scope.** This part sets forth the eligibility, enrollment, and entitlement requirements and procedures for the following:
  - (1) **Supplementary medical insurance.** (The rules about premiums are in [part 408](/cfr/42/part408.md) of this chapter.)
  - (2) The immunosuppressive drug benefit provided for under sections 1836(b) and 1837(n) of the Act, hereinafter referred to as the Part B-Immunosuppressive Drug Benefit (Part B-ID).

## Notes

### Amendments

[53 FR 47204, Nov. 22, 1988, as amended at 87 FR 66505, Nov. 3, 2022]

### Authority

Authority: 42 U.S.C. 1302, 1395p, 1395q, and 1395hh.

### Source

Source: 53 FR 47204, Nov. 22, 1988, unless otherwise noted.

### Amendments

[53 FR 47204, Nov. 22, 1988, as amended at 87 FR 66505, Nov. 3, 2022]