Medicare Advantage or Medigap at 65? Look 20 Years Ahead, and Know Your Way Out

Medicare Advantage or Medigap? Most comparisons show you one year. The choice you make at 65 lasts a lot longer than that, and it's the one that's hardest to undo.

Every fall, Medicare shoppers compare next year: this premium, that copay, this drug list. That's the right question for someone already on Medicare. At 65 it's the wrong question, or at least an incomplete one.

At 65 you aren't choosing a plan for a year. You're choosing a path. A typical 65-year-old woman in the U.S. lives about 21 more years. Your health will change along the way, and so will every plan. And in most states the door to Medigap is wide open for exactly six months, then mostly closes.

So the question at 65 is really two questions. What will each path cost me over the next two decades? And if I pick one and it stops fitting, can I get out?

Our cost calculator, Plan and Thrive, now answers the first one. This post walks through what it shows, the risks of the choice at 65, and how to soften each one.

What one year hides

Here is one example from the calculator: a 65-year-old woman in Columbus, Ohio, comparing 2027 plans. It lays her choices out over 22 years, to age 87: her life expectancy of about 21 years, plus one. Each total counts premiums (including Part B), medical costs and drugs. It also counts the chance of a bad year, and her health changing as she ages.

Plan and Thrive calculator, version 0.9.0. "If she's healthy" is her expected year: her usual care plus the chance of an ER visit or a hospital stay. A bad year means reaching the plan's in-network out-of-pocket limit; care outside the network, where a plan covers it, has a higher limit or none. The 22-year totals are in today's dollars (each year's cost adjusted for 3% general inflation). In future dollars they are, from top to bottom: $140,100, $178,800, $200,100 and $229,500 if she starts healthy; $252,800, $291,500, $278,500 and $278,900 if she starts with a heart condition. For education only. This is a rough estimate based on averages, and your costs will differ.

See the numbers for yourself: if she starts healthy or if she starts with a heart condition. Change the ZIP code, age, health or drugs to see your own.

Read it the way a 65-year-old would.

Next year, the Medicare Advantage plan looks unbeatable. It costs about $3,700 less than Plan G in a normal year. But in a bad year it costs nearly twice as much. With Plan G, a bad year costs the same as a good one.

Over 22 years, the gap narrows, and for some people it closes. For someone who starts healthy, Medicare Advantage still comes out well ahead. For someone who starts with a heart condition, the lowest-cost plan finishes about $21,000 below Plan G over 22 years. And for her, if the plan stops giving money back on Part B after a few years, Medicare Advantage ends up costing more than Plan G.

Two assumptions are worth knowing. The long view keeps the Medicare Advantage plan's premium ($0 here) and its money back on Part B at next year's amounts for all 22 years, while the plan's copays and out-of-pocket limit rise about 6% a year and Plan G's premium rises with medical costs and with her age. And the totals leave out dental, vision and hearing care, which many Medicare Advantage plans include and Medigap doesn't, and long-term care, which neither covers.

The totals are not the whole story. The table can't show what happens if, at 72, she wants to switch. That's the exit question, and it's where most of the risk is.

Five risks of the choice at 65, and how to soften each one

1. Easy to leave Medigap, hard to come back

Your Medigap open enrollment period lasts six months, starting with the first month you're 65 or older and enrolled in Part B. During those months, any Medigap insurer must sell you any policy it offers, at its standard price, whatever your health.

After that, in most states, federal law no longer guarantees it. An insurer can ask about your health, charge you more, or turn you down. Ohio, the state in our example, is one of those states.

So the two paths aren't symmetric. Starting with Medigap and later moving to Medicare Advantage is usually easy: you can join a plan every fall. Starting with Medicare Advantage and later moving to Medigap may not be possible, and the people who most want to switch are the ones whose health has changed.

How to soften it:

• Make the decision during your Medigap open enrollment, with the long view in front of you. That is the one time both paths are fully open.
• If you choose Medicare Advantage at 65, know your trial right. If you joined a Medicare Advantage plan when you first became eligible at 65, federal law generally gives you up to 12 months to return to Original Medicare and buy any Medigap policy sold in your state, without health questions. Put the end date on your calendar now. Medicare explains the trial right here.
• Check your state. A few states let people buy or switch Medigap at other times: some year-round (New York and Connecticut, for example), some around their birthday (California and Oregon, among others). The calculator tells you your state's rule beside the long view.

2. Your health will change, and the long view expects it

At 65, most people feel fine about a $9,000 out-of-pocket limit because they don't expect to reach it. The question is how often it will happen over 20 years.

Among Medicare enrollees in 2023, about 12% of people 65 to 74 had a hospital stay during the year. Among people 85 and older, it was about 24%. ER visits rose from about 18% to over 35%. And the mix of health changes: the share of enrollees with a heart or lung condition rises from about a quarter at 65 to 74 to nearly half at 85 and older.

The calculator builds this in. Year 1 is the health you describe. After that, each year blends four common health profiles, moving toward the sicker ones with age the way Medicare enrollees' health does. Each profile is priced under each plan's own rules, so an out-of-pocket limit is counted in the years someone actually reaches it.

How to soften it:

• Compare the bad year, not just the expected one. If you choose Medicare Advantage, keep savings you could actually use: the plan's in-network out-of-pocket limit plus the Part D yearly cap on drugs ($2,400 in 2027, rising each year).
• Run the long view with a sicker starting profile too. If the answer flips, as it does in the Columbus example, ask yourself which risk you'd rather carry.
• Leave the last planned year counted as a high-cost year. Most people are in the hospital at least once in their last year of life. The calculator counts it by default; you can turn it off.

3. Every plan changes every year

A Medicare Advantage plan is a one-year contract. Benefits, copays, networks and drug lists can all change each January.

We compared the 3,386 Medicare Advantage plans open to everyone that were offered in both 2026 and 2027, averaging across plans (not weighted by how many people are in each). Among plans that charge a specialist copay, the average rose 10%, from $34 to $38. The average in-network out-of-pocket limit rose 8.5%, from about $5,680 to about $6,170. The average premium rose 16%, from about $21 to about $25 a month, though most plans charged $0 in both years. Givebacks, the money back on Part B, were the least stable feature for small amounts: of 859 plans giving back less than $50 a month in 2026, 478 ended it in 2027. Larger givebacks held up better. Of 274 plans giving back $150 a month or more, 41 cut it and 27 weren't renewed at all; none of those that continued ended it.

How to soften it:

• Don't choose on the giveback alone. For every plan with money back on Part B, the calculator draws a second line: the same plan if the money back ends after year 3. If the plan only wins with the money back, you're betting on the giveback lasting.
• Recheck every fall. The Annual Enrollment Period runs October 15 through December 7. Read your plan's Annual Notice of Change when it arrives in September.
• Use the January fix. From January 1 through March 31, people in a Medicare Advantage plan can switch to another one, or go back to Original Medicare and add a drug plan, once. (Medicare & You has the rules.) Going back to Original Medicare that way doesn't guarantee you a Medigap policy, though; see risk 1.

4. Medigap's premium rises, and not only with inflation

Plan G is predictable in a bad year, but its premium isn't fixed. In most states, insurers price by age. On Medicare's plan finder, the median Plan G policy priced by age costs about a quarter more at 75 than at 65, about half again more at 80, and about 80% more at 85. On top of that come rate increases: Plan G increases filed in the first quarter of 2026 by six large carriers ranged from just over 12% to more than 26%, according to the consulting firm Telos Actuarial (CBS News).

The calculator grows Plan G's premium 4.5% a year with medical costs, plus the step for your age where the policy is priced by age (high-deductible Plan G: 5% a year, plus the same step). That assumes increases settle back from recent years. As a cross-check, CMS projects Medicare spending per enrollee to grow about 6% a year through 2034. If recent increases persist, Plan G will cost more than the long view shows.

How to soften it:

• Ask how the policy is priced. Community-rated policies charge everyone the same regardless of age. Issue-age policies are priced by your age when you buy, and don't rise because you get older. Attained-age policies rise as you age. The same Plan G benefits can follow very different price paths.
• Look at high-deductible Plan G. It costs much less each month; you pay the first $3,050 of covered costs in 2027, then it pays like Plan G. In the Columbus example it's within about $1,000 of Plan G over 22 years when she starts with a heart condition, and about $21,000 cheaper when she starts healthy (today's dollars).
• Know your state's switching rules before you need them. In a birthday-rule or year-round state, you may be able to move to a cheaper company later without health questions. Elsewhere, assume the company you pick at 65 is the one you'll keep.

5. Networks, referrals and prior authorization

Medigap has no network: any doctor or hospital that takes Medicare takes you, anywhere in the country. Medigap plans also don't differ in benefits. A Plan G pays the same from every company; only the price and the company differ.

Medicare Advantage plans use networks, and many require referrals or prior authorization. That matters more if you travel, split the year between states, or develop a condition that needs a particular specialist.

How to soften it:

• Check your doctors and hospitals in every plan you consider, not just the cheapest.
• Compare a PPO. The calculator always includes the county's pick for seeing doctors outside a network, and you can swap in any plan sold where you live.

Your exit strategy, in one place

Even with a long-view decision, it pays to know every door out:

• Medigap open enrollment: six months from the month you're 65 and in Part B. Any policy, standard price, no health questions.
• The 12-month trial right: for people who joined Medicare Advantage when first eligible at 65, or who dropped a Medigap policy to try Medicare Advantage for the first time. You can apply for Medigap from 60 days before your Medicare Advantage coverage ends until 63 days after.
• Guaranteed-issue rights: for example, if your plan leaves Medicare or your area, you move out of its service area, or qualifying employer coverage ends. You usually have 63 days, so keep every letter that says when coverage ends. Medicare's list is here.
• The Medicare Advantage Open Enrollment Period: January 1 to March 31, one change, for people already in a plan.
• The five-star special enrollment period: if a five-star plan is offered where you live, you can switch to it once between December 8 and November 30. Special enrollment periods are explained here.
• Your state's Medigap rules: birthday rules, anniversary rules or year-round rights in some states. Your state insurance department has the current details.
• The Annual Enrollment Period: October 15 to December 7, for changing plans. But it doesn't give you a right to buy Medigap without health questions.

If you're under 65 and on Medicare because of a disability, the rules differ. Federal law doesn't require companies to sell you a Medigap policy, though some states do. Ask your SHIP counselor what's available where you live.

A checklist for 65

1. Run the long view, not just next year. Use the years you're likely to live, then run it again starting a step sicker.
2. Look at the bad year. Can you pay a Medicare Advantage plan's in-network out-of-pocket limit, plus the drug cap, in the same year? More than once?
3. Read the "if the money back ends" line for any plan with a Part B giveback.
4. Ask how each Medigap policy is priced, and what your state lets you do later.
5. Check doctors, hospitals and drugs in every plan on your list.
6. Decide inside your Medigap open enrollment. If you choose Medicare Advantage, put your trial-right deadline on the calendar.
7. Talk it through. Your State Health Insurance Assistance Program (SHIP) gives free, unbiased Medicare counseling. A licensed financial planner can help you weigh the costs against your savings and income.

The bottom line

Medicare Advantage can be the right choice at 65, especially if you're healthy, your doctors are in network, and you can carry a bad year. Original Medicare with Medigap can be the right choice, especially if you value predictable costs, freedom to see any doctor, and keeping both doors open. Neither is right for everyone.

What's different at 65 is that the choice comes with a deadline, and the cheaper path next year isn't always the cheaper path for the next twenty. Before you enroll, look at the long view and ask: what happens if this stops fitting, and will I still be able to choose?

[Run your own numbers in the Plan and Thrive calculator →](https://www.65thrive.org/calculator/) Your ZIP code, your health and your drugs, plan by plan, for next year and the years ahead.

For education only. This is a rough estimate based on averages, and your costs will differ. Talk with a licensed financial planner and your free [SHIP counselor](https://www.shiphelp.org/) before you decide.