; special enrollment period and limit on late enrollment penalties (1) Application of part B deemed enrollment process to residents of Puerto Rico Section 1837(f)(3) of the Social Security Act ( 42 U.S.C. 1395p(f)(3) ) is amended by striking , exclusive of Puerto Rico . (2) Effective date The amendment made by paragraph (1) shall apply to individuals whose initial enrollment period under section 1837(d) of the Social Security Act begins on or after the first day of the effective month, specified by the Secretary of Health and Human Services under section 1839(j)(1)(C) of such Act, as added by subsection (c)(2). (3) Transition providing special enrollment period and limit on late enrollment penalties for certain Medicare beneficiaries Section 1839 of the Social Security Act ( 42 U.S.C. 1395r ) is amended— (A) in the first sentence of subsection (b), by inserting subject to section 1839(j)(2), after subsection (i)(4) or (l) of section 1837,