42 C.F.R. § 411.104 : Public Health — CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES — MEDICARE PROGRAM — EXCLUSIONS FROM MEDICARE AND LIMITATIONS ON MEDICARE PAYMENT — LIMITATIONS ON PAYMENT FOR SERVICES COVERED UNDER GROUP HEALTH PLANS: GENERAL PROVISIONS — Current employment status

(a) General rule. An individual has current employment status if-
(1) The individual is actively working as an employee, is the employer (including a self-employed person), or is associated with the employer in a business relationship; or
(2) The individual is not actively working and-
(i) Is receiving disability benefits from an employer for up to 6 months (the first 6 months of employer disability benefits are subject to FICA taxes); or
(ii) Retains employment rights in the industry and has not had his employment terminated by the employer, if the employer provides the coverage (or has not had his membership in the employee organization terminated, if the employee organization provides the coverage), is not receiving disability benefits from an employer for more than 6 months, is not receiving disability benefits from Social Security, and has GHP coverage that is not pursuant to COBRA continuation coverage ( 26 U.S.C. 4980B; 29 U.S.C. 1161 - 1168; 42 U.S.C. 300bb-1 et seq.). Whether or not the individual is receiving pay during the period of nonwork is not a factor.
(b) Persons who retain employment rights. For purposes of paragraph (a)(2) of this section, persons who retain employment rights include but are not limited to-
(1) Persons who are furloughed, temporarily laid off, or who are on sick leave;
(2) Teachers and seasonal workers who normally do not work throughout the year; and
(3) Persons who have health coverage that extends beyond or between active employment periods; for example, based on an hours bank arrangement. (Active union members often have hours bank coverage.)
(c) Coverage by virtue of current employment status. An individual has coverage by virtue of current employment status with an employer if-
(1) the individual has GHP or LGHP coverage based on employment, including coverage based on a certain number of hours worked for that employer or a certain level of commissions earned from work for that employer at any time; and
(2) the individual has current employment status with that employer, as defined in paragraph (a) of this section.
(d) Special rule: Self-employed person. A self-employed individual is considered to have GHP or LGHP coverage by virtue of current employment status during a particular tax year only if, during the preceding tax year, the individual's net earnings, from work in that year related to the employer that offers the group health coverage, are at least equal to the amount specified in section 211(b)(2) of the Act, which defines "self-employment income" for social security purposes.
(e) Special Rule: members of religious orders and members of clergy -
(1) Members of religious orders who have not taken a vow of poverty. A member of a religious order who has not taken a vow of poverty is considered to have current employment status with the religious order if-
(i) The religious order pays FICA taxes on behalf of that member; or
(ii) The individual is receiving cash remuneration from the religious order.
(2) Members of religious orders who have taken a vow of poverty. A member of a religious order whose members are required to take a vow of poverty is not considered to be employed by the order if the services he or she performs as a member of the order are considered employment only because the order elects social security coverage under section 3121(r) of the IRC. This exemption applies retroactively to services performed as a member of the order, beginning with the effective dates of the MSP provisions for the aged and the disabled, respectively. The exemption does not apply to services performed for employers outside of the order.
(3) Members of the clergy. A member of the clergy is considered to have current employment status with a church or other religious organization if the individual is receiving cash remuneration from the church or other religious organization for services rendered.
(f) Special rule: Delayed compensation subject to FICA taxes. An individual who is not working is not considered an employee solely on the basis of receiving delayed compensation payments for previous periods of work even if those payments are subject to FICA taxes (or would be subject to FICA taxes if the employer were not exempt from paying those taxes). For example, an individual who is not working in 1993 and receives payments subject to FICA taxes for work performed in 1992 is not considered to be an employee in 1993 solely on the basis of receiving those payments.

42 C.F.R. §411.104