Best Medicare Supplement Plans 2026 — Complete Medigap Guide

Best Medicare Supplement Plans 2026 — Complete Medigap Guide

Medicare Supplement Insurance (Medigap) fills the gaps that Original Medicare doesn't cover — including Part B deductibles, coinsurance, and hospital costs. If you're approaching 65 or already on Medicare, choosing the right Medigap plan is one of the most consequential financial decisions you'll make in retirement.

The bad news: there are 10 standardized Medigap plans (A, B, C, D, F, G, K, L, M, N) and premiums vary dramatically by carrier for identical coverage. The good news: this guide cuts through the noise so you can make a confident decision.

How Medigap Plans Work — The Basics

Medigap is sold by private insurers but standardized by the federal government. Plan G from Aetna has identical coverage to Plan G from Mutual of Omaha — the only difference is premium price and customer service. This makes comparison shopping straightforward if you know what to look for.

Key Medigap rules:

• You must have Medicare Part A and Part B to buy Medigap
• The best time to buy is during your Medigap Open Enrollment (6 months starting the month you turn 65 AND enroll in Part B)
• During open enrollment, insurers cannot deny you coverage or charge more due to pre-existing conditions
• After open enrollment, medical underwriting can result in higher premiums or denial of coverage

The 10 Medigap Plans — What's Covered

Plan G is currently the most popular plan for new Medicare beneficiaries. Here's how the key plans compare:

Plan G vs. Plan N — Which Is Better in 2026?

Plan G covers everything including Part B excess charges (which can add up if you see doctors who don't accept Medicare assignment). Premiums are higher but predictability is maximum.

Plan N trades a few copays (up to $20 for some office visits, up to $50 for ER) for lower monthly premiums — typically 15–25% less than Plan G. Good for healthy people who don't expect frequent doctor visits.

For most retirees, Plan G is the better choice if you can afford the premium. The Part B excess charge coverage alone can save you thousands if your doctors don't accept Medicare assignment.

What Medigap Doesn't Cover

Medigap does NOT cover:

• Medicare Part D (prescription drug coverage — you need a separate PDP plan)
• Vision, dental, or hearing aids
• Long-term care
• Private-duty nursing
• Medicare Advantage plans (you can't use Medigap with MA)

2026 Medigap Premium Benchmarks

Medigap premiums vary by age, location, gender, and tobacco use. Here are 2026 approximate ranges for a 65-year-old non-smoker (before inflation adjustments):

• Plan G: $140–$260/month depending on carrier and location
• Plan N: $110–$190/month
• Plan K: $70–$130/month (covers 50% of cost-sharing)

Always compare at least 4–5 carriers in your area. The same Plan G can cost $180/month with one insurer and $240/month with another — that's $720/year in savings for identical coverage.

When to Buy: Medigap Open Enrollment Window

Your Medigap Open Enrollment begins the month you turn 65 AND are enrolled in Medicare Part B. This window lasts 6 months — after it closes, you can still buy Medigap, but insurers can charge more or deny coverage based on health conditions.

Critical warning: If you delay Part B enrollment because you're still working with employer coverage, your Medigap open enrollment won't start until you actually enroll in Part B. The clock starts then — not when you turn 65.

How to Shop for Medigap in 2026

Use these steps to find the best plan at the lowest price:

1. Identify your enrollment window — confirm when your Part B coverage starts
2. Get quotes from at least 5 carriers — major carriers include: Aetna, Mutual of Omaha, Cigna, United Healthcare, Blue Cross Blue Shield (varies by state), Manhattan Life
3. Use a Medicare agent — they're free to you (commissions paid by the carrier) and can show all available plans in your zip code
4. Beware of high-pressure "guaranteed issue" sales — some agents push plans during open enrollment that aren't the best value
5. Re-evaluate every 3–5 years — Medigap premiums increase with age; a carrier that was cheapest at 65 may not be cheapest at 75

RetireStack's Free Medicare Compare Tool

Use RetireStack's free Medicare Compare tool to see available Medigap plans in your state, compare premiums by carrier, and run IRMAA calculations to factor Medicare costs into your full retirement plan. No signup required.

Compare Medicare Plans Free →

FAQ: Medicare Supplement Plans (Medigap)

Is Plan G better than Plan F? Plan G requires you to pay the Part B deductible ($257 in 2026) yourself each year, while Plan F covered it in full. Since Plan F is no longer available to new beneficiaries (as of January 1, 2020), Plan G is the most comprehensive plan available to new Medicare enrollees. The premium savings of Plan G over Plan F typically outweigh the deductible cost.

Can I switch Medigap plans later? Yes, but after your open enrollment window closes, you may need medical underwriting. Some states (New York, Connecticut, Massachusetts, Missouri, Oregon) have guaranteed issue laws that allow Medigap switching regardless of health. In most other states, a health review may be required and premiums may increase based on your health status.

How do I know if a Medigap plan is legitimate? All Medigap plans are standardized by federal law and must include "Medicare Supplement Insurance" in the plan name. Be wary of any plan promising "new" or "improved" Medigap coverage — all changes must be approved by state insurance departments. Verify any agent's license at your state's Department of Insurance website.

What's the difference between Medigap and Medicare Advantage? Medigap works WITH Original Medicare (Parts A + B) to fill coverage gaps. Medicare Advantage (Part C) REPLACES Original Medicare with a private plan that often includes Part D and extra benefits. You cannot have both. Most people choosing Medigap prefer the flexibility and predictability of Original Medicare.

How do Medigap premiums increase over time? Medigap premiums typically increase each year due to: (1) Attained-age pricing (premiums rise as you age — most common), (2) Community pricing (same premium regardless of age), or (3) No-age-rated (same premium at any age — rare). Ask your insurer which pricing model they use before buying.

Bottom Line

Medigap Plan G is the right choice for most pre-retirees in 2026: it's the most comprehensive coverage available, premiums are predictable, and no medical underwriting is required during your open enrollment window. Get quotes from at least 5 carriers before committing — the same coverage can cost $100+/month more with the wrong insurer. Use RetireStack's free Medicare Compare tool to see all plans and premiums available in your state.