Medicare 2026

Medicare Advantage or Medigap? The Deadlines That Shape Your Choice

NEW HAVEN, Conn. — Choosing between Original Medicare paired with a Medigap policy and a Medicare Advantage plan is one of the biggest decisions a new enrollee makes. But it isn't only a question of which path fits your health and budget. It's also a question of when — because the calendar quietly decides which doors stay open to you and which ones can close.

The two paths are built differently. Original Medicare (Parts A and B) is the federal program, and a Medigap policy is private insurance that helps pay the out-of-pocket costs Original Medicare leaves behind. Most people on that path also add a stand-alone Part D drug plan. Medicare Advantage (Part C) bundles Parts A, B and usually D into one private plan that follows federal rules but runs its own network and cost structure.

Both paths are available to people in New Haven. New Haven is in New Haven County, where multiple Medicare Advantage plans and stand-alone Part D plans are offered each year. But the choice between the two structures is shaped as much by enrollment windows as by the plans themselves.

The first deadline: your Medigap Open Enrollment Period

The most important date on the Medigap side isn't in the fall — it's tied to your own birthday. Your six-month Medigap Open Enrollment Period begins the month you're 65 and enrolled in Part B. During that window, insurers must sell you any Medigap policy they offer at their best available rate, regardless of your health history.

Miss it, and in most states insurers can use medical underwriting to decide whether to sell you a Medigap policy at all, or at what price. Connecticut has stronger consumer protections than many states, but the safest moment to lock in a Medigap policy is still that first six-month window. If you're leaning toward the Original Medicare + Medigap path, this is the deadline that matters most.

The fall deadline: Oct. 15 – Dec. 7

The Annual Enrollment Period (AEP), Oct. 15 through Dec. 7, is the main window most people know. During AEP you can:

• Switch from Original Medicare to a Medicare Advantage plan, or vice versa.
• Join, drop or change a stand-alone Part D drug plan.
• Change from one Medicare Advantage plan to another.

Whatever you choose during AEP takes effect Jan. 1. If you do nothing, you generally stay in whatever coverage you have now. That's fine if your plan still fits — but plans change every year, so it's worth checking the Annual Notice of Change your carrier mails in September.

Important: AEP lets you move between the two paths, but moving from Medicare Advantage back to Original Medicare during AEP does not guarantee you can buy a Medigap policy. That's the trap many people don't see coming.

The early-year window: Jan. 1 – March 31

The Medicare Advantage Open Enrollment Period (MA-OEP) runs Jan. 1 through March 31 and applies only to people already enrolled in a Medicare Advantage plan. During this window, you can make one change: switch to a different Advantage plan, or drop your Advantage plan and return to Original Medicare (and pick up a Part D plan).

Again, dropping an Advantage plan during MA-OEP does not automatically give you the right to buy any Medigap policy you want. Whether you can — and at what price — depends on state rules and whether you qualify for a "guaranteed issue" right.

What happens if you miss a window

Missing an enrollment window has different consequences depending on which one you miss:

• Missing your initial Part B enrollment can trigger a lifetime late-enrollment penalty and gaps in coverage.
• Missing your Medigap Open Enrollment Period can mean paying more later, or being turned down, unless you qualify for a special guaranteed-issue right.
• Missing a Part D enrollment window without other creditable drug coverage can trigger a lifetime Part D late-enrollment penalty.
• Missing AEP usually means waiting a full year to change plans, unless you qualify for a Special Enrollment Period (for example, if you move out of your plan's service area or lose other coverage).

Special Enrollment Periods exist for life events, but they're specific — don't assume one will be there when you need it.

How the two paths interact with Part D drug costs in 2026 and 2027

Whichever path you pick, Part D rules apply. The Part D maximum deductible is $615 in 2026 and $700 in 2027. Out-of-pocket spending on covered drugs is capped at $2,100 in 2026 and $2,400 in 2027. The old "donut hole" coverage gap has been eliminated as of 2025, leaving three payment phases. Medicare's Prescription Payment Plan is also available if you'd like to spread drug costs across the year in monthly installments instead of paying at the pharmacy counter.

Higher-income enrollees should also know about IRMAA — the income-related surcharge on Part B and Part D premiums, which in 2026 begins above $109,000 in income for a single filer. IRMAA follows you on either path.

A simple way to think about the timing

If you're new to Medicare, work backward from your Part B start date. Your Medigap Open Enrollment Period clock starts then, and it doesn't reset. If you're already enrolled and reconsidering, mark AEP (Oct. 15–Dec. 7) on your calendar, and — if you're currently in an Advantage plan — know that MA-OEP (Jan. 1–March 31) gives you one more chance early in the year.