The timing of your Medigap enrollment can have a dramatic effect on what you pay — and whether you can get coverage at all. Understanding your enrollment windows before you turn 65 is one of the most important steps in Medicare planning.
Your Open Enrollment Period: The Best Time to Buy
Your 6-Month Open Enrollment Window
Your Medigap Open Enrollment Period begins on the first day of the month you turn 65 and are enrolled in Medicare Part B. It lasts exactly 6 months. This is the single most important enrollment window you have — and it only happens once.
During your Open Enrollment Period, federal law guarantees you the right to buy any Medigap plan sold in your state — at standard rates — regardless of your health history. Carriers cannot:
- Deny you coverage
- Charge you more due to pre-existing conditions
- Make you wait before coverage begins for pre-existing conditions
Once this window closes, most states allow carriers to use medical underwriting — meaning they can reject your application or charge significantly higher premiums based on your health.
What If You Delay Part B?
Still working at 65 with employer coverage — If you or your spouse are still working and have group health insurance through an employer, you may be able to delay Part B without penalty. Your Medigap Open Enrollment Period will begin when you eventually enroll in Part B — not when you turn 65. Make sure the employer plan is considered “creditable coverage” before delaying.
Retired before 65 with COBRA or marketplace coverage — If you’re using COBRA or a marketplace plan as a bridge to Medicare, you should enroll in Medicare Part B when you turn 65. Delaying Part B in this situation triggers a permanent late enrollment penalty and delays your Medigap Open Enrollment window.
Enrolled in Medicare Advantage at 65 — If you choose Medicare Advantage at first and later want to switch to Original Medicare with a Medigap plan, you may face underwriting in most states. However, during your first 12 months in Medicare Advantage, you have a trial right that allows you to switch back to Original Medicare and buy a Medigap plan with guaranteed issue.
Enrollment Windows at a Glance
| Situation |
Guaranteed Issue? |
Notes |
| Age 65 + enrolled in Part B (Open Enrollment) |
✓ Yes |
Best time to buy. 6-month window, any plan, standard rates. |
| Losing employer group health coverage |
✓ Yes |
Qualifying life event. 63-day window after coverage ends. |
| Medicare Advantage — first 12 months (trial right) |
✓ Yes |
One-time right to return to Original Medicare + Medigap. |
| Medicare Advantage plan leaves market / loses contract |
✓ Yes |
Involuntary disenrollment triggers guaranteed-issue rights. |
| Moving out of Medicare Advantage service area |
✓ Yes |
Relocation outside plan’s service area qualifies. |
| Applying outside of any qualifying window |
✗ No |
Subject to medical underwriting in most states. May be denied or charged higher rates. |
Under 65 and on Medicare?
If you qualify for Medicare before age 65 due to disability or ESRD, federal law does not require carriers to sell you a Medigap plan — though some states (like CT, MA, and NY) mandate coverage. In states without protections, you may need to wait until you turn 65 to buy a Medigap plan with guaranteed-issue rights. Call us to find out what’s available in your state.
Guaranteed-Issue Rights Beyond Open Enrollment
Even after your Open Enrollment Period closes, certain life events can trigger guaranteed-issue rights — meaning you can buy a Medigap plan without underwriting. These include losing other coverage, moving, or having your plan discontinued. See the full list:
View all guaranteed-issue qualifying events →
State Protections That May Help
Year-round open enrollment states — Connecticut, Massachusetts, Maine, New York, and Washington require carriers to accept all applicants year-round at standard rates, regardless of health. If you’re in one of these states, timing is less critical — though buying early still locks in lower attained-age premiums.
Birthday rule states — Several states including California, Idaho, Illinois, Louisiana, Missouri, Nevada, Oklahoma, and Oregon allow you to switch Medigap plans around your birthday each year without underwriting — as long as you move to a plan with equal or lesser benefits. This gives you an annual window to shop for lower premiums on the same coverage.
Not Sure When to Enroll? Let’s Talk.
We’ll review your situation — retirement date, current coverage, and health history — and tell you exactly when and how to apply for the best outcome. Free, no-obligation consultation.
📞 Call 1-888-972-0024
