Should I choose Medigap or Medicare Advantage first?

The safer question is not which one sounds better today. It is which choice keeps the other choice open later. Medicare Advantage is easy to enter each year, but moving back to Original Medicare with a Medicare Supplement, also called Medigap, can require health approval after your first protected window closes.

Revised: 8/17/26
Jason Baar
Fee-Only Medicare Advisor
NPN #2033715

The order matters because the door only swings easily one way

Every year during the Annual Election Period, October 15 - December 7, anyone on Medicare can join, change, or drop a Medicare Advantage plan with no health questions.

The guarded direction is the other way.

If you later want Original Medicare plus a Medigap policy, the insurance company may be allowed to use medical underwriting. Underwriting means the company reads your health history, asks about diagnoses and medications, and can charge more, exclude conditions, or decline the application.

In most states, once your one-time 6-month Medigap window has closed, there is no annual reset. That is the asymmetry. Medicare Advantage has a yearly doorway. Medigap often does not.

Your protected Medigap windows

Your main Medigap protection is the one-time 6-month Medigap Open Enrollment Period. It starts the first month you are both age 65 or older and enrolled in Medicare Part B. If you legitimately delay Part B, the Medigap window waits too.

A second protection is the 12-month Medicare Advantage trial right. This applies only if your first Medicare coverage decision at age 65 was Medicare Advantage. For 12 months from the day that coverage starts, you can drop the Medicare Advantage plan, return to Original Medicare, and buy Medigap with guaranteed acceptance. Guaranteed issue means the company must sell you certain Medigap plans without medical underwriting.

There are also federal guaranteed-issue situations, such as losing employer coverage paired with Medicare, your Medicare Advantage plan ending in your area, or moving out of your plan’s service area. These usually create a 63-day window for certain Medigap plans.

A small number of states have their own year-round or birthday-rule Medigap access. Florida is not one of them. Florida has no annual birthday-based switching right.

The three paths put the risk in different places

Original Medicare alone means Part A, Part B, and usually a standalone Part D drug plan. It gives wide access. About 89% of non-pediatric office-based physicians accept new Medicare patients, according to KFF, a nonpartisan health policy research nonprofit. But Original Medicare alone has no annual out-of-pocket ceiling. After the Part B deductible, Medicare usually pays 80% of most outpatient care and you pay the other 20%. A serious diagnosis can create five- or six-figure exposure in a bad year.

Medicare Advantage, also called Part C, is a private plan that replaces how you receive Original Medicare. It has an in-network out-of-pocket cap. The 2026 federal ceiling is $9,250, though many plans set a lower number. PPO plans also have a $13,900 combined in-and-out-of-network cap. Medicare Advantage plans work through networks that can change each year. On average, Medicare Advantage enrollees can reach about 48% of the physicians their Original Medicare neighbors can, according to KFF, with wide plan-to-plan variation. Most Medicare Advantage plans include Part D drug coverage and many add dental, vision, or hearing extras. The cap resets every January.

Original Medicare plus Medigap plus Part D gives wide access because Medigap sits on top of Original Medicare. It usually creates a more predictable worst case: the Medigap premium plus small deductibles. Medigap premiums vary, often between $100 and $300 a month in 2026 for the most popular plan, Plan G. Current Medigap policies do not include drug coverage, so a standalone Part D plan sits alongside.

Neither path is wrong. They place the risk in different places.

If Medigap might ever matter, decide during the window

The practical rule is simple: sequence is strategy.

If Medigap might be part of your plan now or years from now, the 6-month Medigap Open Enrollment Period is when that decision gets made. After that, the question may no longer be “Which option do I prefer?” It may become “Which company, if any, will accept me?”

That does not mean everyone should buy Medigap. It means you should understand what you are giving up before the protected window closes.

Medigap letters matter more than company names

Medigap benefits are standardized by federal law. Every Medigap plan with the same letter has identical medical benefits. Every Plan G pays the same claims the same way, whether the company name is familiar or not.

What differs is the premium, the rating method, household or spouse discounts, and underwriting standards.

The shopping rule is: shop the letter, not the brand.

There is one exception. Outside protected windows, underwriting standards differ by carrier. One company’s no is not every company’s no.

The 12-month trial right has to be used in the right order

If your first Medicare coverage decision at age 65 was Medicare Advantage, write down the date that plan started. Then write down the date 12 months later and mark it “trial right expires.”

If you decide to use the trial right, apply for the Medigap policy first. Confirm that it is issued and has an effective date. Then disenroll from the Medicare Advantage plan and add a standalone Part D plan.

Do not reverse that order. Dropping the Medicare Advantage plan before the Medigap policy is issued can leave a coverage gap.

See the rest of Jason’s free Medicare PDFs in the Free Medicare Guides library.