; (ii) receive requests for any additional information necessary for enrollment in writing; and (iii) as a consequence of such enrollment are deemed, for such continuous period as such annuitant or family member involved otherwise maintains eligibility for enrollment under Medicare part B, to have elected to be enrolled under Medicare part B (under section 1837(m)(1) of the Social Security Act) in connection with the enrollment in a Program plan under this chapter; and (B) the Office provides the Secretary of Health and Human Services and the Commissioner of Social Security in a timely manner with such information respecting such annuitants and family members and such election as may be required to effect their enrollment and coverage under Medicare part B and this section in a timely manner. (f) Medicare coordination (1) In general The Office shall require each Program plan to provide benefits for covered Medicare individuals pursuant to the standard coordination of benefits method used under this chapter, rather than the exclusion method or the carve-out method. (2) Medicare part D prescription drug benefits The Office shall require each Program plan to provide prescription drug benefits for Postal Service annuitants and family members who are eligible individuals (as defined in section 1860D–1(a)(3)(A) of the Social Security Act) through an employer group waiver plan offered under subsection (b) of section 1860D–22 of the Social Security Act. (g) Postal Service contribution (1) In general Subject to subsection (i), for purposes of applying section 8906(b) to the Postal Service, the weighted average shall be calculated in accordance with paragraphs (2) and (3). (2) Weighted average calculation Not later than October 1 of each year (beginning with 2019), the Office shall determine the weighted average of the rates established pursuant to subsection (c)(2) for Program plans that will be in effect during the following contract year with respect to— (A) enrollments for self only; (B) enrollments for self plus one