Part twelve of Healthcare in Retirement, timed for the week the license plates start changing. The people in this one do not call themselves snowbirds on the phone. They describe a schedule. "We half the year in Arizona, half the year in Connecticut." "I'm going back and forth like a snowbird thing from here to New York doing the six months here, six months there." And the one that got my attention: "We moved from Arizona to Massachusetts, and I don't know if you guys can still help us or not." Three families, three different answers, and the difference between them is the county line.
The situation
You have a house in Scottsdale and a house near your grandkids. You are on a Medicare Advantage plan you like. You leave in May and come back in November. Somewhere in that schedule are two rules that decide whether the plan is still yours when you get home, and neither of them cares how nice the plan is.
Advantage plans are county products
Medicare: "Insurance companies can decide if a plan will be available to everyone with Medicare in a state, or only in certain counties." To join one, Medicare's booklet lists three requirements, and the second is "Live in the plan's service area." The regulation says the same thing in its own way: an enrollee "Resides in the service area of the MA plan." And the plan can end it: "A Medicare Advantage Plan can disenroll you for several reasons, like if you move outside the plan's service area."
How much choice you have depends on the county too. KFF counts an average of 32 Advantage plans with drug coverage per beneficiary for 2026, but the same brief says people in urban counties choose from 42 plans while people in the most rural counties choose from 20. Medicare's state sheet shows 133 Advantage plans available in Arizona for 2026 and 105 in Nevada. The county line matters twice: which plans exist where you sleep, and whether yours will keep you.
The six-month rule
This is the regulation, and I want you to read it as written. Under 42 CFR 422.74(d)(4)(ii): "If the individual has not moved from the MA plan's service area… but has left the service area… for more than 6 months, the MA organization must disenroll the individual from the plan, unless the exception in paragraph (d)(4)(iii) of this section applies."
Must. It sits under a heading called "Required disenrollment." A plan is not being unkind when it drops a member who stayed away seven months. It is following the rule. And here is the part that surprised me: the same section says a member is "considered to be temporarily absent from the plan service area" when required plan mail "is returned to the MA organization by the U.S. Postal Service as undeliverable and a forwarding address is not provided." Returned mail can start the clock. Keep your forwarding current and tell the plan your seasonal address.
Now the exception. Some plans offer what the rule calls a visitor or traveler benefit. If they do, "the MA organization may elect to offer to the individual the option of remaining enrolled" for an absence longer than six months but less than twelve, at the same cost sharing as at home. Three things to notice. "May elect," so it is the plan's choice, and many plans do not offer it. The plan can limit which areas qualify. And even with it, "The individual is disenrolled on the first day of the 13th month after the individual left the service area." Six months is the default ceiling. Some plans stretch it toward twelve. Ask yours, in writing, before you leave.
Visiting is not moving, and that is the whole problem
Read the regulation again. "Has not moved… but has left." Those are two different people. The one who left for seven months and kept her Arizona address is dropped under the six-month rule. Medicare does not publish a special enrollment period for absence the way it does for a move, so do not assume one exists. If this happens to you, ask immediately whether any period applies to your situation, because the default is Original Medicare with no drug plan.
The one who actually moved gets two doors. The first is a Special Enrollment Period. Medicare: "Your chance to switch begins when you move and continues for 2 full months after you move." Better: "If you tell your plan before you move, your chance to switch plans begins the month before the month you move and continues for 2 full months after you move." Same two months on the back end either way, so telling the plan first buys an extra month at no cost. And if you do nothing, "you'll be enrolled in Original Medicare when you're dropped from your old Medicare Advantage Plan."
The second door is the one from part five. Moving out of a plan's service area is on Medicare's list of guaranteed-issue rights for a Supplement, with the deadline "No more than 63 days after your Medicare Advantage Plan coverage ends," and the same catch as always: "You only have this right if you switch to Original Medicare (rather than join another Medicare Advantage Plan)." The 63 days run from the day coverage ends, not the day the truck left.
What happens to a doctor visit in the other state
Before any of that, there is the ordinary question: you are in Connecticut in July and you need to see someone. If your plan is an HMO, Medicare says "You generally must get your care and services from doctors, other health care providers, and hospitals in the plan's network, except: Emergency care, Out-of-area urgent care, Temporary out-of-area dialysis." Everything else, "you may have to pay the full cost." Urgent care, per Medicare, means "a sudden illness or injury that isn't a medical emergency and/or life threatening." A refill appointment is not that. A follow-up for the knee is not that.
If your plan is a PPO, the sentence is friendlier: "You can generally go to out-of-network providers for covered services, but you'll usually pay more." Covered, at a price. So the first thing a two-address family should know about its own plan is which of those two sentences applies to it.
The plan that has no county line
Original Medicare does not have one. "You can use any doctor or hospital that takes Medicare, anywhere in the U.S.," which Medicare defines as the 50 states, the District of Columbia, and five territories. A Supplement rides along: "You can keep your current Medigap policy no matter where you live, as long as you still have Original Medicare." The premium may change with a new permanent address, and switching companies after a move can mean "answer some medical questions," but the policy itself travels. For a household that spends real time in two states every year, that is a structural difference worth putting on the table.
Drug plans sit in between. Part D is sold by region, not by county. There are 34 regions nationally, a plan "must offer a Part D plan that serves at least an entire PDP region," and Arizona and Nevada each had 10 stand-alone drug plans for 2026. Your plan's network of pharmacies in the other state is a question worth asking, and Thursday's article on preferred pharmacies explains why the answer can change your copay. Mail order, shipped to the right porch, solves a lot of it.
One more line, for the caller heading south for the winter: "Original Medicare generally doesn't cover medical care outside the U.S.", and Advantage plans "generally don't cover medical care outside the U.S." either. Mexico is a separate conversation, and some Supplements have a foreign-travel emergency benefit, capped and time-limited, that belongs in it.
What a Certified Medicare Planner® does differently
They ask for both addresses and the dates before they ask about benefits. They read which sentence your plan lives under, HMO or PPO, and tell you what a routine visit in the other state actually costs. They ask the plan, in writing, whether it offers a visitor benefit and for how long, and they put the six-month date on the calendar the day you leave. They know the difference between visiting and moving, and when a move is real, they tell the plan before the truck comes, because it buys a month, and they start the 63-day Supplement clock from the right day. And for a family that will do this every year, they put Original Medicare plus a Supplement on the table next to the Advantage plan and run the whole year, both houses, before anyone picks. The advisors are at 602-281-3898.
Friday, October 2. Foothills Library, Glendale, 10:30 AM. Mustang Library, Scottsdale, 2:30 PM. No cost. Register at 123easymedicare.com/medicare-workshop or call (877) 220-1089.
Healthcare in Retirement continues this week. If there is a corner of Medicare that has ever confused you, tell us, and it may be the next one we take apart.
This event is presented by 123EasyMedicare, a brand of American Retirement Advisors, an independent, private organization. It is not sponsored by, endorsed by, or affiliated with Medicare, the Centers for Medicare & Medicaid Services, the Social Security Administration, or any government agency. The libraries are not sponsors of, and are not affiliated with, this event. Educational only; not tax, legal, or insurance advice.
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Disclaimer: This article is for educational purposes only. It is not sponsored, endorsed, or otherwise representative of Medicare or the federal Medicare program. American Retirement Advisors is not a government agency. For official Medicare information, visit medicare.gov or call 1-800-MEDICARE (1-800-633-4227).