Predictable costs. Freedom to see any doctor. Medigap fills the gaps Original Medicare leaves behind — so a serious illness doesn't become a financial crisis.
Medicare Supplement Insurance — commonly called Medigap — is private health insurance designed to work alongside Original Medicare (Parts A & B). It helps pay the out-of-pocket costs that Original Medicare doesn't fully cover, including deductibles, copayments, and coinsurance.
Without supplemental coverage, Original Medicare only pays about 80% of approved medical costs. You're responsible for the other 20% — with no annual out-of-pocket maximum. For someone with a serious condition, that 20% can add up to tens of thousands of dollars. Medigap closes that gap and gives you cost predictability.
Key rule: You must be enrolled in both Medicare Part A and Part B before you can purchase a Medigap policy. Medigap is separate from and does not include prescription drug coverage — you'll still need a standalone Part D plan for prescription drugs.
When you receive medical care, Medicare pays its share first. Then your Medigap policy pays its portion — covering some or all of the remaining cost, depending on which plan you have. In many cases, you pay $0 at the point of service.
Medigap plans are sold by private insurance companies, but the plans themselves are federally standardized. This means a Plan G from Aetna offers exactly the same benefits as a Plan G from Mutual of Omaha or Blue Cross Blue Shield — the only difference is the monthly premium. This makes it easy to shop by price once you've chosen your plan letter.
The most important time to buy Medigap is during your Medigap Open Enrollment Period: the 6-month window that begins the first month you're 65 or older and enrolled in Part B. During this period, insurance companies cannot deny you coverage or charge you more due to pre-existing health conditions. This is a one-time window — it does not repeat annually.
After this period, you may be subject to medical underwriting, which means an insurer can deny you coverage or charge significantly higher premiums based on your health history.
There are 10 standardized Medigap plans available in most states, labeled A through N. The most popular plans in Arizona are Plan G and Plan N.
| Benefit | Plan A | Plan B | Plan D | Plan G ⭐ | Plan K | Plan L | Plan M | Plan N ⭐ |
|---|---|---|---|---|---|---|---|---|
| Part A Coinsurance & Hospital Costs (up to 365 days) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Part B Coinsurance or Copayment | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | Copays apply |
| Blood (First 3 Pints) | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Part A Hospice Care Coinsurance | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Skilled Nursing Facility Coinsurance | ✗ | ✗ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Part A Deductible | ✗ | ✓ | ✓ | ✓ | 50% | 75% | 50% | ✓ |
| Part B Deductible | ✗ | ✗ | ✗ | ✗ | ✗ | ✗ | ✗ | ✗ |
| Part B Excess Charges | ✗ | ✗ | ✗ | ✓ | ✗ | ✗ | ✗ | ✗ |
| Foreign Travel Emergency (80%) | ✗ | ✗ | ✓ | ✓ | ✗ | ✗ | ✓ | ✓ |
⭐ = Most popular plans in Arizona. Plan F is no longer available to those who became eligible for Medicare on or after January 1, 2020.
Plan G is the most comprehensive Medigap plan available to new Medicare beneficiaries. It covers everything Plan F used to cover, except for the Part B deductible ($257/year in 2025). After you meet your Part B deductible each year, Plan G covers 100% of your approved Medicare costs — including Part B excess charges (what non-participating doctors can charge above Medicare's approved rate). It also covers 80% of foreign travel medical emergencies.
Plan N offers very strong coverage at a lower monthly premium than Plan G. The trade-offs are small: you pay up to $20 per office visit and up to $50 per emergency room visit (waived if admitted). Plan N does not cover Part B excess charges, so you'll want to confirm your doctors accept Medicare assignment.
No network restrictions: With any Medigap plan, you can see any doctor or specialist in the country who accepts Medicare — no referrals needed, no network to stay in. This is a significant advantage over Medicare Advantage for those who travel frequently or want complete freedom of choice.
Medigap premiums vary by insurance company, your age, gender, tobacco use, and zip code — but the benefits are identical for each plan letter. In Tucson, typical monthly premiums for a 65-year-old non-smoker range roughly from $80–$130/month for Plan N and $100–$175/month for Plan G. These are estimates — we'll give you exact quotes from all available carriers when you connect with us.
The right answer depends entirely on your health, lifestyle, and budget. Here's a quick comparison:
We can walk you through a personalized side-by-side comparison. Request a free callback and we'll do the math together.