Last verified: April 19, 2026.

Medigap Open Enrollment Period

The six-month one-time window that protects your right to buy any Medigap policy without medical underwriting.

Written by The Medicare Desk editorial team.

What this window is

A six-month one-time window that begins on the first day of the month a person is both age 65 or older and enrolled in Medicare Part B. The window cannot be reset by delaying Part B enrollment past age 65 in most cases, and it does not repeat.

What triggers it

Enrollment in Medicare Part B at age 65 or later. The clock starts the first day of the month in which both conditions are first met.

What happens if you miss it

Outside the Medigap OEP, federal law does not guarantee issue. Carriers may use medical underwriting and may decline coverage, charge higher premiums, or impose pre-existing condition waiting periods. Some states layer additional guaranteed-issue rights or birthday rules; consult the relevant state reference card.

Why this window matters

The Medigap Open Enrollment Period is the only time federal law requires every Medigap carrier to issue a policy regardless of health status. State law layers additional protections in many states, but the federal floor is this six-month window.

How to verify these claims

Every claim on this page traces to a primary federal source listed in the reference card below. URLs are re-verified on the cadence shown at the top of the card.

Reference card: Medicare enrollment period

Medigap Open Enrollment Period (Medigap OEP)

As of: April 19, 2026
Next refresh due: January 15, 2027
Cross check status: Under human review

Window: A six-month one-time window that begins on the first day of the month a person is both age 65 or older and enrolled in Medicare Part B. The window cannot be reset by delaying Part B enrollment past age 65 in most cases, and it does not repeat.
Triggering event: Enrollment in Medicare Part B at age 65 or later. The clock starts the first day of the month in which both conditions are first met.
Penalty if missed: Outside the Medigap OEP, federal law does not guarantee issue. Carriers may use medical underwriting and may decline coverage, charge higher premiums, or impose pre-existing condition waiting periods. Some states layer additional guaranteed-issue rights or birthday rules; consult the relevant state reference card.

Sources

Primary sources, federal

42 USC 1395ss(s), Open Enrollment Period for Medicare Supplemental Policies-> https://www.law.cornell.edu/uscode/text/42/1395ss
42 CFR 403.205, NAIC Model Regulation incorporated by CMS-> https://www.ecfr.gov/current/title-42/chapter-IV/subchapter-A/part-403/subpart-B

Counseling and operational

CMS, Choosing a Medigap Policy guide-> https://www.medicare.gov/Pubs/pdf/02110-medigap-guide-health-insurance.pdf

Source snapshots preserved; URLs verified on the cadence above.

Editorial independence. The Medicare Desk is an independent editorial publication of Tojocu LLC. We do not sell insurance, do not accept commissions or fees from insurance carriers, and are not paid to recommend any plan or company. We do not collect contact information for the purpose of connecting consumers with agents.

Not insurance advice specific to you. The information on this site is general educational content and is not insurance, legal, tax, or financial advice. Coverage rules, premiums, and program features change. Always verify current details with the official source listed on each page and with a licensed professional in your state before making a decision.

Not affiliated with the U.S. government or the federal Medicare program. The Medicare Desk is a privately operated editorial site. It is not endorsed by, affiliated with, or operated by the Centers for Medicare and Medicaid Services, the Social Security Administration, or any other federal agency.

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