Medicare Advantage

Nashua's Medicare Annual Enrollment Period: Key Oct.15–Dec.7 Dates

NASHUA, N.H. — The calendar has turned, which means Medicare's second big enrollment window is now open. From January 1 through March 31, people already enrolled in a Medicare Advantage plan have a chance to make one change — a narrower opportunity than the fall Annual Enrollment Period, but an important one for anyone who woke up in January realizing their new plan isn't the right fit.

Here in Nashua, that timing matters. The city sits in Hillsborough County, where plan availability is set at the county level and where the rules for switching mid-season are strict about who can do what, and when.

What the Medicare Advantage Open Enrollment Period actually is

The Medicare Advantage Open Enrollment Period (often shortened to MA-OEP) is a do-over window. It exists because people sometimes discover, after their new plan starts on January 1, that a doctor isn't in-network, a medication isn't covered the way they expected, or the plan structure just doesn't work for them.

It is not the same as the fall Annual Enrollment Period (Oct. 15 – Dec. 7), when almost any Medicare beneficiary can shop and switch. MA-OEP is narrower on purpose.

Who can use this window — and who cannot

You can use MA-OEP if, as of January 1, you are enrolled in a Medicare Advantage plan (with or without drug coverage).

You cannot use MA-OEP if you are on Original Medicare (Part A and Part B) with or without a stand-alone Part D drug plan. This is the mistake we hear most often in Nashua: a reader on Original Medicare assumes January opens the door to jump into an Advantage plan. It does not. For that move, you generally have to wait for the next fall AEP or qualify for a Special Enrollment Period (for example, moving out of your plan's service area, losing other coverage, or qualifying for Extra Help).

What changes you can make between Jan. 1 and March 31

During this window, you get one change. Your options are:

• Switch from your current Medicare Advantage plan to a different Medicare Advantage plan.
• Drop your Medicare Advantage plan entirely and go back to Original Medicare.
• If you drop back to Original Medicare, you can also enroll in a stand-alone Part D prescription drug plan at the same time.

What you cannot do during MA-OEP:

• Switch from one stand-alone Part D plan to another (that's an AEP move).
• Join a Part D plan if you're staying on Original Medicare and didn't previously have one.
• Use the window more than once. The first change you make locks in; a February switch means no March switch.

Your new coverage generally starts the first day of the month after the plan receives your enrollment request.

How the dates interact — and what happens if you miss them

The two windows work together, but they do different jobs:

• Oct. 15 – Dec. 7 (AEP): the broad shopping window. Almost anyone with Medicare can join, switch, or drop Advantage and Part D plans. Changes take effect January 1.
• Jan. 1 – March 31 (MA-OEP): the correction window, for people already on a Medicare Advantage plan as of Jan. 1.

If you miss both, you're generally locked in for the rest of the year unless you qualify for a Special Enrollment Period. SEPs are triggered by specific life events — a move, loss of employer coverage, gaining or losing Medicaid eligibility, and a handful of others listed at medicare.gov.

One more date worth keeping in mind: Medigap (Medicare Supplement) rules are separate. If you drop an Advantage plan mid-year and want a Medigap policy instead, medical underwriting may apply in New Hampshire outside of specific guaranteed-issue situations. That's worth a call to the state's SHIP counselors before you make the switch.

A quick note on the Part D numbers you'll see quoted

Even though MA-OEP isn't about picking a Part D plan from scratch, the drug-cost rules still shape your decision to stay or switch. For 2026, CMS has set the Part D out-of-pocket cap at $2,100 and the maximum Part D deductible at $615. The old coverage gap ("donut hole") was eliminated in 2025, so Part D now has three phases instead of four. The Medicare Prescription Payment Plan also remains available if you'd like to spread drug costs across the calendar year in monthly installments.

Where to get unbiased help in Nashua

Before you make your one MA-OEP change, it's worth talking to someone who doesn't sell plans:

• Medicare.gov — the official plan-comparison tool, current for Hillsborough County.
• 1-800-MEDICARE (1-800-633-4227), available 24/7.
• New Hampshire's SHIP program (ServiceLink Resource Center) offers free, one-on-one Medicare counseling to Nashua-area residents.