Medicare Advantage

Medicare Advantage or Medigap? Know Your Cambridge Deadlines

# Medicare Advantage or Medigap? Understanding the two…

CAMBRIDGE, Mass. — Choosing between Original Medicare with a Medigap policy or a Medicare Advantage plan is one of the biggest decisions a new enrollee makes. But the choice isn't just about coverage style — it's also about the calendar. Miss a key window, and the door to one path can close or become much harder to walk through later.

Cambridge sits in Middlesex County, where 9 carriers offered 49 Medicare Advantage plans in 2026, and Medicare Part D drug coverage is folded into those plans rather than sold as stand-alone options. The 2027 lineup appears in each plan's Annual Notice of Change and on Medicare.gov's Plan Finder. With that many choices on the table, understanding when to decide matters just as much as what to decide.

The two paths, in plain terms

Original Medicare (Parts A and B) is the federal program. Many people pair it with a Medigap (supplement) policy to help cover out-of-pocket costs, and add a stand-alone Part D drug plan. Medicare Advantage (Part C) is different — it's a private plan that replaces how you get your Parts A and B benefits, and usually bundles in drug coverage.

You can only be in one system at a time. And the rules about when you can move between them are strict.

Your first window: turning 65

When you first become eligible for Medicare, you get a 7-month Initial Enrollment Period — the three months before your 65th birthday month, your birthday month, and the three months after.

This window matters for two reasons:

1. It's when you sign up for Part B without a late penalty. 2. It triggers your Medigap Open Enrollment Period — a one-time, 6-month window (starting when you're 65 and enrolled in Part B) when insurers must sell you any Medigap policy they offer, at their best available rate, regardless of your health history.

Miss that Medigap window, and in most states insurers can ask health questions later and either charge more or turn you down. That's the single biggest timing trap for people choosing between the two paths.

The fall window: Oct. 15 to Dec. 7

The Annual Enrollment Period (AEP) runs from October 15 through December 7 every year. During AEP you can:

• Join, switch, or drop a Medicare Advantage plan.
• Join, switch, or drop a Part D drug plan.
• Move from Medicare Advantage back to Original Medicare.

Changes made during AEP take effect January 1.

One important nuance: AEP lets you leave Medicare Advantage for Original Medicare, but it does not guarantee you a Medigap policy. That's a separate question governed by state and federal rules.

The winter window: Jan. 1 to March 31

The Medicare Advantage Open Enrollment Period runs January 1 through March 31. If you're already in a Medicare Advantage plan, you get one chance during this window to:

• Switch to a different Medicare Advantage plan, or
• Drop Medicare Advantage and return to Original Medicare (and, if you like, pick up a Part D plan).

Again — returning to Original Medicare is allowed. Getting a Medigap policy to go with it is a separate step, and outside a guaranteed-issue window, an insurer can typically underwrite.

What happens if you miss a window

Missing your Initial Enrollment Period for Part B can mean a lifelong late-enrollment penalty added to your Part B premium. Missing your one-time Medigap Open Enrollment window can mean paying more later — or being declined — if your health has changed. Missing AEP usually means waiting a full year, 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 specific life events, but you can't count on one just because you change your mind.

Why timing shapes the choice

Because Medigap protections are strongest at age 65, many people who think they might ever want Original Medicare + Medigap consider starting there. Others prefer the bundled structure of Medicare Advantage from day one. Neither approach is universally right — it depends on your doctors, your medications, your travel patterns, and your budget.

Middlesex County had 49 Medicare Advantage plans available across 9 carriers in 2026, giving Cambridge residents plenty to compare during AEP; the 2027 lineup is detailed in each plan's Annual Notice of Change and on Medicare.gov's Plan Finder. Stand-alone Part D plans aren't sold in this area, so drug coverage under the Medicare Advantage path generally comes built into the plan, while Original Medicare enrollees typically get their drug coverage through a Part D plan sold in the broader state market.

Part D's annual out-of-pocket cap is $2,100 in 2026 and $2,400 in 2027. The maximum Part D deductible a plan can charge is $615 in 2026 and $700 in 2027. These figures apply whether your drug coverage rides inside a Medicare Advantage plan or a stand-alone Part D plan.

Where to get personal help

Medicare decisions are personal, and the timing rules can be unforgiving. Free, unbiased help is available:

• Medicare.gov — official plan comparisons and enrollment.
• 1-800-MEDICARE (1-800-633-4227) — 24/7 help line.
• SHINE, the Massachusetts State Health Insurance Assistance Program (SHIP) — free one-on-one counseling for Cambridge residents.