Most people think signing up for Medicare means their healthcare costs are covered. They’re not — and the gap can be devastating.
Original Medicare (Parts A and B) covers roughly 80% of most medical costs. The remaining 20%? That’s your responsibility. With no annual out-of-pocket maximum in Original Medicare Part B, a serious illness, surgery, or extended hospital stay can leave you with $10,000, $20,000, or more in bills — regardless of how long you’ve paid into the system.
That’s where Medicare Supplement Insurance (also called Medigap) comes in. And in 2026, choosing the right Medigap plan — or even knowing to get one — is one of the most important financial decisions a senior can make.
This guide breaks down exactly what each plan covers, which plans most people actually choose, and how to avoid the most expensive Medicare mistake seniors make.
What Is Medicare Supplement Insurance (Medigap)?
Medigap is private health insurance sold by insurance companies to fill the “gaps” in Original Medicare. It helps pay costs like copayments, coinsurance, and deductibles that Original Medicare doesn’t cover. Depending on the plan, Medigap can cover nearly 100% of your out-of-pocket Medicare costs.
There are 10 standardized Medigap plans, labeled A through N. Each plan with the same letter offers the same core benefits regardless of which insurance company sells it — so Plan G from Blue Cross is identical to Plan G from Aetna or Cigna in what it covers. The only difference is the premium you pay, which can vary significantly between companies.
The 10 Medicare Supplement Plans at a Glance (2026)
| Plan | Part A Coinsurance | Part B Coinsurance | Part A Deductible | Part B Deductible | Part B Excess Charges | Foreign Travel |
|---|---|---|---|---|---|---|
| Plan A | ✅ | ✅ | ❌ | ❌ | ❌ | ❌ |
| Plan B | ✅ | ✅ | ✅ | ❌ | ❌ | ❌ |
| Plan C* | ✅ | ✅ | ✅ | ✅ | ❌ | ✅ 80% |
| Plan D | ✅ | ✅ | ✅ | ❌ | ❌ | ✅ 80% |
| Plan F* | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ 80% |
| Plan G ⭐ | ✅ | ✅ | ✅ | ❌ | ✅ | ✅ 80% |
| Plan K | ✅ 50% | ✅ 50% | ✅ 50% | ❌ | ❌ | ❌ |
| Plan L | ✅ 75% | ✅ 75% | ✅ 75% | ❌ | ❌ | ❌ |
| Plan M | ✅ | ✅ | ✅ 50% | ❌ | ❌ | ✅ 80% |
| Plan N ⭐ | ✅ | ✅ (copays apply) | ✅ | ❌ | ❌ | ✅ 80% |
* Plans C and F are not available to beneficiaries who became eligible for Medicare on or after January 1, 2020.
The 2 Plans Most Seniors Actually Choose in 2026
Plan G — The Most Popular Comprehensive Plan
Plan G is now the most widely purchased Medigap plan in the country, and for good reason. It covers everything Medicare Supplement plans cover — except the Part B deductible ($257 in 2026). Once you pay that deductible once per year, Plan G pays 100% of your remaining Medicare-approved costs for the rest of the year.
What Plan G costs: Monthly premiums typically range from $100–$200/month for a healthy 65-year-old, depending on your location, insurer, and tobacco use. That’s $1,200–$2,400/year in premiums, in exchange for virtually zero additional out-of-pocket costs on Medicare-covered services.
Best for: Seniors who want maximum coverage, see doctors or specialists frequently, have chronic conditions, or simply want to know their healthcare costs are fully predictable.
Plan N — The Best Value Plan for Healthy Seniors
Plan N offers nearly the same coverage as Plan G, with two differences: it does not cover Part B excess charges (the small amount some doctors who don’t accept Medicare assignment can charge above Medicare rates), and it has small copayments — up to $20 for office visits and up to $50 for ER visits that don’t result in inpatient admission.
What Plan N costs: Monthly premiums are typically 15–25% lower than Plan G, often $80–$160/month for a 65-year-old. If you’re relatively healthy, use mostly in-network Medicare-accepting providers, and don’t make many ER visits, the lower premiums can make Plan N significantly cheaper overall.
Best for: Healthy, active seniors who want solid coverage at a lower premium and are comfortable with occasional small copayments.
The Most Expensive Medicare Mistake Seniors Make
The single most costly mistake? Choosing Medicare Advantage instead of Original Medicare + Medigap without understanding the difference — and then needing serious medical care.
Medicare Advantage plans (Part C) often look appealing because they have $0 monthly premiums and include dental/vision/hearing benefits that Medigap doesn’t. But Medicare Advantage comes with networks, prior authorizations, and significant out-of-pocket costs when you actually get sick:
- Maximum out-of-pocket limits in 2026: up to $9,350 in-network or $14,000 combined in- and out-of-network
- Prior authorizations required for many specialist visits, procedures, and medications
- Network restrictions — your preferred doctor may not be covered
- Plans can change their benefits each year, often reducing coverage
None of these limitations exist with Original Medicare + Medigap. You can see any doctor or specialist in the country who accepts Medicare, with no referrals, no networks, no prior authorizations — and with Plan G or Plan N, near-zero out-of-pocket costs.
How to Get the Best Medigap Rate in Your Area
Because every insurer sells the same standardized plan letter but charges different premiums, shopping around is essential. Here’s the right process:
- Use Medicare’s official plan finder at medicare.gov to see which insurers offer plans in your ZIP code and their listed premium ranges.
- Work with a licensed independent Medicare broker — they can compare multiple insurers on your behalf at no cost to you (brokers are paid by the insurance company, not by you). The key word is “independent” — they should offer plans from multiple companies, not just one.
- Consider the insurer’s rate increase history — some companies offer low introductory premiums that increase sharply after year 2 or 3. Ask the broker to show you the rate increase history for any plan you’re considering.
- Apply during your Open Enrollment window — the 6-month period starting the month you turn 65 and enroll in Medicare Part B is your guaranteed issue window. Insurers cannot deny you coverage or charge you higher rates due to health history during this window. Outside it, most states allow medical underwriting — meaning you can be denied or charged more if you have pre-existing conditions.
What Medicare Does NOT Cover (And What to Do About It)
Even with the best Medigap plan, there are significant healthcare costs Medicare doesn’t cover at all:
| Gap | Typical Annual Cost | Solution |
|---|---|---|
| Prescription Drugs | $500–$5,000+/year | Medicare Part D plan (separate purchase) |
| Dental Care | $500–$3,000+/year | Standalone dental insurance or dental savings plan |
| Vision (glasses, contacts) | $200–$600/year | Standalone vision plan or VSP/EyeMed membership |
| Hearing Aids | $2,000–$6,000 per pair | Hearing benefit plans, Costco Hearing Aids, or OTC hearing aids (FDA approved since 2022) |
| Long-Term Care | $50,000–$100,000+/year | Long-term care insurance or hybrid life/LTC policy |
| Routine Foot Care | $300–$800/year | Check if your state Medicaid covers it, or standalone plan |
Medicare Supplement vs. Medicare Advantage: The Honest Comparison
| Factor | Original Medicare + Medigap | Medicare Advantage |
|---|---|---|
| Monthly premium | Higher ($100–$200 + Part B premium) | Often $0 (but Part B premium still applies) |
| Out-of-pocket max | ~$257/year with Plan G | Up to $9,350–$14,000/year |
| Doctor choice | Any Medicare-accepting doctor, nationwide | Network only (HMO or PPO) |
| Referrals required | No | Often yes (especially HMO) |
| Prior authorization | Rarely | Frequently |
| Dental/Vision included | No (separate purchase) | Often yes (basic benefits) |
| Plan stability | Very stable — benefits don’t change | Benefits change annually |
| Best if you… | Have chronic conditions, travel often, want predictability | Are healthy, stay local, want $0 premium |
Frequently Asked Questions
Can I switch from Medicare Advantage back to Original Medicare and get a Medigap plan?
Yes, but it’s complicated outside of your guaranteed issue window. Most states require you to pass medical underwriting to get a Medigap plan if you’re switching from Medicare Advantage after your first year. A handful of states (CT, MA, ME, NY) have year-round guaranteed issue rights. If you’re in your first year with Medicare Advantage, you have a Special Enrollment Period to return to Original Medicare with guaranteed Medigap rights.
What is the Part B deductible in 2026?
The Medicare Part B deductible is $257 in 2026 (up from $240 in 2025). This is the only cost you pay with Medigap Plan G before your supplement coverage kicks in.
Is there a Medigap plan that covers dental?
No current Medigap plan includes dental, vision, or hearing benefits. These must be purchased separately. Some insurers offer bundles that pair a Medigap plan with a dental/vision rider, which can simplify billing and sometimes reduce total premium costs.
What is the income limit for Medicare Savings Programs?
Medicare Savings Programs help low-income beneficiaries pay Medicare premiums and cost-sharing. In 2026, the individual income limit is approximately $1,275/month for the Qualified Medicare Beneficiary (QMB) program, and slightly higher for the Specified Low-Income Medicare Beneficiary (SLMB) and QI programs. These limits vary by state. Contact your State Health Insurance Assistance Program (SHIP) for free, unbiased advice — call 1-800-MEDICARE to be connected.