Quick answer: how to buy a Medicare Supplement plan
1. You must be enrolled in Original Medicare (Parts A and B) first.
2. Your one-time 6-month Medigap Open Enrollment Period starts the month you turn 65 AND are enrolled in Part B — every plan is guaranteed-issue with no health questions. Outside this window, most states allow medical underwriting.
3. Pick a standardized plan letter — Plan G, Plan N, or High-Deductible Plan G are the three most popular for new enrollees in 2026.
4. Compare every carrier in your state. Coverage is federally standardized — only price and rate-increase history differ.
5. Premium is identical whether you enroll through a licensed independent agent or directly with the carrier — agents are paid by the carrier, not by you.
How to buy a Medicare Supplement plan in 2026
Buying a Medigap plan is a 5-step process. The biggest risk isn't paperwork — it's missing the guaranteed-issue window.
Step 1 — Confirm enrollment in Medicare Parts A and B
You must be enrolled in Original Medicare (Parts A + B) before buying a Medigap policy. If you're turning 65, enroll in Part B during your 7-month Initial Enrollment Period — the 3 months before your birthday month, your birthday month, and the 3 months after. Enrolling in the 3 months before gives you the earliest coverage start.
Step 2 — Identify your Medigap Open Enrollment window
Your Medigap Open Enrollment is a one-time 6-month window starting the month you turn 65 AND are enrolled in Part B. During this window:
- Every Medigap plan in your state is guaranteed-issue
- Carriers cannot ask health questions
- Carriers cannot decline you or charge more for pre-existing conditions
- No waiting periods for benefits
Outside this window, most states allow medical underwriting — a carrier can decline you or charge more for conditions. Missing this window is the most expensive Medicare mistake new enrollees make.
A few states have additional protections: Year-round guaranteed-issue (CT, ME, MA, NY, VT); Birthday Rule for one switch per year (CA, ID, IL, KY, LA, MD, MN, NV, OK, OR); Anniversary Rule (MO).
Not sure if you're inside your Medigap Open Enrollment window?
Get A Free Quote — We'll Check For You →Step 3 — Choose the right standardized plan letter
Medigap plans are federally standardized by letter — Plan G's coverage is identical no matter which carrier sells it. For new enrollees in 2026, three plans dominate:
| Plan | Typical monthly premium (2026) | Best for |
|---|---|---|
| Plan G | $110 – $200 | Most popular for new enrollees. Covers everything except the Part B deductible. Widest predictable coverage. |
| Plan N | $90 – $160 | ~$30/mo less than Plan G. Adds $20 office copay, $50 ER copay (waived if admitted). |
| HD Plan G | $40 – $70 | Lowest premium. Federal annual deductible (~$2,870). Good for healthy enrollees who want catastrophic-only coverage. |
Plan F covers even more than Plan G — but it is closed to anyone Medicare-eligible after January 1, 2020. Existing Plan F enrollees can keep it; newly eligible beneficiaries cannot buy it.
Step 4 — Compare every carrier in your state
Coverage for the same plan letter is federally standardized — Plan G from Mutual of Omaha covers exactly the same things as Plan G from Aetna. Only price and rate-increase history differ.
Why carrier choice matters even with standardized coverage: premiums increase over time, and switching carriers later usually requires medical underwriting. A carrier with the lowest premium today isn't always the cheapest 5-10 years from now. A good independent agent ranks carriers by both starting premium AND historical rate stability.
Step 5 — Get free quotes from a licensed independent agent
A licensed independent agent quotes every major carrier in your state at no cost. Your premium is identical to enrolling directly with the carrier — agents are paid a commission by the carrier, not by you. The benefit: you compare every option in one place instead of contacting each carrier individually.
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Get A Free Quote →Free · No obligation · Premium identical to enrolling directly
Common mistakes when buying a Medicare Supplement plan
How much does a Medicare Supplement plan cost in 2026?
Medigap premiums vary by state, age at enrollment, ZIP code, gender (in most states), and tobacco use. Typical premium ranges for new enrollees age 65 in 2026:
- Plan G: $110 – $200/month — most popular choice
- Plan N: $90 – $160/month — ~$30/mo savings vs Plan G with $20 office / $50 ER copays
- High-Deductible Plan G: $40 – $70/month — lowest premium; federal annual deductible
Premiums in California, Florida, New York, and Texas typically run on the higher end; states with smaller senior populations often run lower.
Ready to buy?
Request a free quote below. A licensed independent Medicare agent will quote every major carrier in your state, walk you through the standardized plan options, and help you complete enrollment at no cost.