When does an enrollment made during the annual election period take effect?
An enrollment made during the Annual Election Period (AEP, October 15–December 7) takes effect January 1 of the following year.
What the rule says
“For an election or change of election made during the annual coordinated election period as described in § 422.62(a)(2)(i), coverage is effective as of the first day of the following calendar year except that for the annual coordinated election period described in § 422.62(a)(2)(ii), elections made after December 31, 2005 through May 15, 2006 are effective as of the first day of the first calendar month following the month in which the election is made.”
“Except as provided under paragraph (b)(2) of this section, for an enrollment or change of enrollment in Part D made during an annual coordinated election period as described in § 423.38(b), the coverage or change in coverage is effective as of the first day of the following calendar year.”
“Beginning in 2011, the annual coordinated election period for the following calendar year is October 15 through December 7.”
The CMS guidance confirms this timing for the current AEP:
“Occurs: October 15–December 7 every year Effective date: January 1 of the following year Who can use: All Medicare beneficiaries Changes permitted:”
This last point relies on the CY 2027 enrollment guidance, which applies to enrollment requests received on or after January 1, 2027, and may be applied by plans to AEP enrollments effective January 1, 2027.
Carrier and FMO rules are often stricter than CMS rules. This tool reports what CMS sources say and is not legal advice. Enrollment guidance shown is the CY 2027 version. Regulation text reflects the CY 2027 marketing rules, which apply to marketing beginning October 1, 2026.
This answer was generated by mapdbot from the sources listed below on September 23, 2026 and checked against them. Regulation text: eCFR as of 09/15/2026. It is for licensed insurance agents, is not legal advice, and does not cover carrier or FMO rules.
Sources cited
Related questions
- When does the annual election period run?
- Can a client join a PDP during the annual coordinated election period?
- Can I enroll this client today, or do they have to wait until AEP?
- What effective date should I put on the application if I submit it today?
- Does a Medicare Advantage plan have to accept my client's application if they apply during the annual election period?