42 CFR § 407.21 - Special enrollment period for volunteers outside the United States.
(a) General rule. A SEP, as defined in § 406.24(a)(4) of this subchapter, is provided for an individual who does not elect to enroll or to be deemed enrolled in SMI when first eligible, or who terminates SMI enrollment, if the individual meets the following requirements:
(1) The individual is serving as a volunteer outside of the United States in a program that covers at least a 12-month period.
(2) The individual is in a program that is sponsored by an organization described in section 501(c)(3) of the Internal Revenue Code of 1986 and is exempt from taxation under section 501(a) of the Internal Revenue Code of 1986.
(b) Duration of SEP. The SEP is the 6-month period beginning on the first day of the month that includes the date that the individual no longer satisfies the provisions of paragraph (a) of this section.
(c) Effective date of coverage. Coverage under a SEP authorized by this section, begins on the first day of the month following the month in which the individual enrolls.