A Medicare Supplement policy sits alongside Original Medicare and pays the share Medicare leaves behind — the deductibles, the coinsurance, the 20% that has no ceiling. You keep Original Medicare, you add a Medigap policy, and you buy a separate Part D drug plan.
Why Arizona is different
Two things make this decision unusual here.
Snowbirds. A large share of Arizona's Medicare population spends part of the year somewhere else. Medicare Advantage plans are built around a local network — outside the service area you are generally limited to emergency care. A Medigap policy works with any provider in the country who accepts Medicare, with no network and no referrals. If you spend months in Minnesota, Michigan or anywhere else, that difference is the whole decision.
Retirement communities. Sun City, Sun City West, Green Valley and similar communities hold some of the densest Medicare populations in the United States. Carriers compete hard for them, which is good for you — but it also means a lot of marketing, and Medigap premiums between carriers for the identical policy can differ substantially.
Plan G and Plan N
Medigap letters are standardised by federal law. Plan G from one carrier covers exactly what Plan G from another covers. Only the premium, the service and the carrier's rate history differ.
- Plan G covers everything Medicare Part A and Part B leave behind except the annual Part B deductible, which is $283 in 2026. After that, covered services are paid in full.
- Plan N works the same way but you pay the Part B deductible plus copays of up to $20 for some office visits and up to $50 for an emergency room visit that does not lead to admission. It also does not cover Part B excess charges.
Plan N usually carries a lower premium. Whether it is the better buy depends on how often you see a doctor — and that is an arithmetic question we can do with you in a few minutes.
The window that does not come back
You get a six-month Medigap open enrolment period beginning the month you are both 65 and enrolled in Part B. During it, no carrier can turn you down or charge you more for your health history.
After it closes, that protection is gone. Outside limited guaranteed-issue situations, Arizona carriers may use medical underwriting — and unlike a handful of other states, Arizona has no annual "birthday rule" letting existing policyholders switch without health questions. That makes the initial six-month window more consequential here than in states that offer a second chance every year.
This is the single most common expensive mistake we see: choosing Medicare Advantage at 65, then trying to move to Medigap at 72 and discovering that health history now stands in the way.
What it does not include
Medigap does not cover prescriptions. You need a separate Part D plan, and skipping it creates a permanent late-enrolment penalty. Medigap also does not cover dental, vision, hearing or long-term care.
Common questions
Is Plan G or Plan N better in Arizona?
It depends on how often you see a doctor. Plan N has a lower premium but adds copays of up to $20 for some office visits and up to $50 for an emergency room visit that does not lead to admission, and it does not cover Part B excess charges. For frequent visits Plan G often costs less overall despite the higher premium. It is a straightforward calculation once you know your usual pattern.
I spend summers out of state. Does Medigap make more sense?
Usually yes. Medigap works with any provider nationwide who accepts Medicare, with no network and no referrals. Medicare Advantage plans are built around a local network and generally cover only emergency care outside the service area. For Arizona snowbirds this is often the deciding factor.
Does Arizona have a Medigap birthday rule?
No. A small number of states — including Nevada and California — give existing Medigap policyholders an annual window to switch policies without medical underwriting. Arizona does not. That makes your initial six-month Medigap open enrolment window at 65 more important here, because there is no yearly second chance.
Can I be turned down for Medigap in Arizona?
Not during your six-month Medigap open enrolment period, which begins the month you are both 65 and enrolled in Part B. Outside that window, and outside specific guaranteed-issue situations such as losing employer coverage, carriers may use medical underwriting and can decline you.
