Medicare Supplement Open Enrollment
vs Annual Open Enrollment
Understanding these two completely different enrollment periods can save you thousands of dollars and prevent coverage gaps. Here's everything you need to know.
Quick Answer: They're Completely Different
Medicare Supplement Open Enrollment is a one-time, 6-month window when you turn 65 where you can get any Medigap plan without health questions.
Annual Open Enrollment is the yearly period (Oct 15 - Dec 7) when you can change Medicare Advantage or Part D prescription drug plans.
⚠️ Confusing these two periods is one of the most expensive Medicare mistakes people make.
Side-by-Side Comparison
Medicare Supplement
Open Enrollment Period
When It Happens
6 months starting the first day of the month you turn 65 AND are enrolled in Medicare Part B
What You Can Do
Enroll in ANY Medigap plan (A, B, C, F, G, K, L, M, N) offered in your state
Health Questions
NONE - Guaranteed Issue Rights apply
Coverage Denial
CANNOT be denied for health reasons
Premium Rates
Standard rates - cannot charge more due to health
Frequency
ONE TIME ONLY - you never get this protection again
Medicare Annual
Open Enrollment Period
When It Happens
Every year from October 15 - December 7
What You Can Do
Change Medicare Advantage plans, switch from Advantage to Original Medicare, change Part D prescription plans
Health Questions
NONE for Medicare Advantage and Part D
Coverage Denial
CANNOT be denied for Medicare Advantage or Part D
Medigap Plans
NOT AVAILABLE - this period doesn't cover Medigap
Frequency
EVERY YEAR - annual opportunity to make changes
Common Costly Mistakes to Avoid
❌ Mistake #1: Waiting for Annual Open Enrollment to Get Medigap
Many people think they can wait until October to enroll in a Medicare Supplement plan during Annual Open Enrollment.
Reality: Annual Open Enrollment does NOT cover Medigap plans. You'll face health underwriting and possible denial.
❌ Mistake #2: Missing the 6-Month Window
Some people delay enrolling in Medicare Part B, not realizing it affects their Medigap Open Enrollment Period.
Reality: Your 6-month period doesn't start until you're enrolled in Part B. Delaying Part B delays your guaranteed issue rights.
❌ Mistake #3: Choosing Medicare Advantage First "To Save Money"
Some people choose Medicare Advantage at 65 thinking they can always switch to Medigap later.
Reality: Switching from Advantage to Medigap after your initial enrollment requires health underwriting. You may be denied or pay higher premiums.
When These Enrollment Periods Apply
Turning 65
Your Medigap Open Enrollment Period starts the first day of the month you turn 65 AND have Part B
✓ Guaranteed Issue Rights
Working Past 65
If you have employer insurance and delay Medicare, your Medigap Open Enrollment starts when you enroll in Part B
⚠ Timing is critical
Already on Medicare
If you've been on Medicare for months/years, you've likely missed your Medigap Open Enrollment Period
⚠ Health underwriting required
What You Should Do Now
If You're Approaching 65
Don't wait. Start researching Medigap plans now. Your 6-month guaranteed issue window is your only chance to get coverage without health questions.
If You're Currently 65+
Check if you're still within your 6-month Medigap Open Enrollment Period. If not, you can still apply but may face health underwriting.
Compare Your Options
Use our rate calculator to compare Plan G and Plan N costs in your area. These are the two most popular Medigap plans for new Medicare beneficiaries.
Related Articles
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Plan G vs Plan N Comparison
Interactive comparison tool to help you choose between the two most popular Medigap plans.
Medicare Advantage vs Medigap
Complete guide to choosing between Medicare Advantage and Medicare Supplement insurance.