42 CFR § 424.522 - Additional effective dates.
---
identifier: "/us/cfr/t42/s424.522"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "42 CFR § 424.522 - Additional effective dates."
title_number: 42
title_name: "Public Health"
section_number: "424.522"
section_name: "Additional effective dates."
chapter_name: "CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "B"
subchapter_name: "MEDICARE PROGRAM"
part_number: "424"
part_name: "CONDITIONS FOR MEDICARE PAYMENT"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 1302 and 1395hh."
regulatory_source: "53 FR 6634, Mar. 2, 1988, unless otherwise noted."
cfr_part: "424"
---
# 424.522 Additional effective dates.
(a) *Reassignments.* (1) The effective date of a reassignment of benefits under § 424.80 is the later of the dates identified in § 424.520(d)(1)(i) and (ii).
(2) Retrospective billing in accordance with a reassignment of benefits and as described in § 424.521(a)(1) is permissible if the circumstances in § 424.521(a)(1) are applicable.
(b) *Form CMS-855O enrollment.* The effective date of a Form CMS-855O enrollment is the date on which the Medicare contractor received the Form CMS-855O application if all other requirements are met.
[86 FR 62419, Nov. 9, 2021, as amended at 90 FR 55617, Dec. 2, 2025]