When is the Medicare Annual Enrollment Period in 2026?

The Medicare Annual Enrollment Period (AEP) runs October 15 through December 7 every year. Changes you make take effect January 1 of the following year.

What can I change during Medicare Annual Enrollment?

During AEP you can: switch from Original Medicare to Medicare Advantage (or vice versa), switch between Medicare Advantage plans, join or switch a standalone Part D prescription drug plan. You cannot use AEP to enroll in Medicare for the first time — that requires your Initial Enrollment Period or a Special Enrollment Period.

Can I switch from Medicare Advantage to a Medigap plan during AEP?

Technically yes — you can drop Medicare Advantage and return to Original Medicare during AEP. But adding a Medigap supplement after your initial enrollment window generally requires medical underwriting in most states. If you're denied or rated up, you may be stuck with Original Medicare without a supplement.

What is the Medicare Advantage Open Enrollment Period?

The Medicare Advantage Open Enrollment Period (OEP) runs January 1 through March 31. If you're already enrolled in an MA plan and want to switch to a different MA plan or return to Original Medicare, you have this second window. Changes made during OEP take effect the first day of the following month.

What changed with Part D in 2026?

In 2026 the Inflation Reduction Act's $2,100 out-of-pocket cap on Part D drug costs takes full effect, eliminating the old catastrophic phase. The standard deductible is $615 for 2026. Part D IRMAA surcharges still apply if your income (from 2 years ago) exceeds the thresholds.

Do I need to do anything during AEP if I'm happy with my current plan?

Not necessarily — your Medicare Advantage or Part D plan auto-renews if you take no action. But you should still review your plan's Annual Notice of Change (ANOC), which arrives by September 30. Premiums, formularies, and provider networks can change January 1 even if you don't switch.

What happens to my Medigap plan during AEP?

Medigap plans are separate from the Medicare AEP. Your Medigap policy auto-renews as long as you pay premiums and don't voluntarily drop it. AEP doesn't give you the right to add, change, or drop Medigap — those are governed by your Medigap plan's terms and state law.

Can I use AEP to add dental or vision coverage?

Original Medicare does not cover routine dental, vision, or hearing — and AEP doesn't change that. If you want those benefits, you can switch to a Medicare Advantage plan that includes them during AEP. Standalone dental and vision insurance can generally be purchased at any time.

How do I compare Medicare Part D plans during AEP?

Use the Medicare Plan Finder at medicare.gov. Enter your prescriptions and dosages, and it calculates your estimated annual drug cost for each plan in your area. Compare total cost (premium + deductible + copays) — not just the monthly premium.

When do AEP changes take effect?

All changes made during the Annual Enrollment Period (Oct 15–Dec 7) take effect January 1 of the following year. If you make multiple changes during AEP, only the last election you make takes effect.

Medicare Annual Enrollment Period 2026: What You Can (and Can't) Do

The Medicare Annual Enrollment Period (AEP) runs October 15 through December 7 every year. Any changes you make take effect January 1. This is your main window to switch Medicare Advantage plans, change your Part D drug plan, or move between Original Medicare and Medicare Advantage. Here's what you need to know — and the traps to avoid.

AEP is open right now. The 2026 Annual Enrollment Period runs October 15 – December 7, 2026. Changes take effect January 1, 2027. Jump to the plan-comparison checklist →

What you can change during AEP

During the Annual Enrollment Period you can make any of the following elections:

Change	Allowed during AEP?	Takes effect
Switch from Original Medicare → Medicare Advantage	Yes	January 1
Switch from Medicare Advantage → Original Medicare	Yes	January 1
Switch between two Medicare Advantage plans	Yes	January 1
Join a standalone Part D drug plan (if you have Original Medicare)	Yes	January 1
Switch between Part D plans	Yes	January 1
Drop a Part D plan	Yes (but late-enrollment penalties apply if you go uninsured later)	January 1
Enroll in Medicare for the first time	No — requires Initial Enrollment Period or SEP	N/A
Add or change a Medigap (Medicare Supplement) plan	No — requires underwriting in most states	N/A

If you make multiple changes during AEP, only your last election before December 7 is the one that takes effect.

The Medigap switching trap

This is the most expensive mistake retirees make during AEP. Here's how it happens:

You enrolled in Medicare Advantage at 65 to save on premiums.
Now at 70 or 75, you've had health issues and want the flexibility of Original Medicare + Medigap.
You drop Medicare Advantage during AEP and return to Original Medicare — that part works fine.
You apply for a Medigap Plan G supplement — and the insurer declines you or charges a much higher premium because of your health history.

The problem: Medigap guaranteed-issue rights only apply during your initial 6-month Open Enrollment Period (the six months starting the month you first have Part B at age 65 or older). After that window closes, insurers in most states can medically underwrite you — meaning a diabetes diagnosis, heart condition, or prior cancer treatment can result in denial or surcharges of 50–200% above standard rates.

Before dropping Medicare Advantage during AEP, confirm you can get a Medigap plan at a reasonable rate. See Medigap Plan G vs Plan N →

2026 Part D changes: the $2,100 out-of-pocket cap

The most significant Part D change in years took full effect in 2026. Under the Inflation Reduction Act, Part D now has a hard $2,100 annual out-of-pocket cap on drug costs.¹ This eliminates the old catastrophic coverage phase where you previously owed 5% of drug costs with no ceiling.

Standard Part D deductible: $615 (2026)² — some plans waive this for preferred generics
Base beneficiary premium: $38.99/month (2026)² — actual plan premiums vary; many plans charge more or less
Part D IRMAA still applies if your 2024 MAGI exceeded $106,000 (single) / $212,000 (MFJ) — surcharges from $13.70 to $85.80/month on top of your plan premium³

If you take expensive specialty medications, the cap is the most valuable change in AEP 2026. Compare plans using Medicare Plan Finder at medicare.gov, entering your specific drugs and dosages.

Part D IRMAA alert: If your 2024 income was above the IRMAA thresholds, you'll owe a surcharge on top of your Part D premium — regardless of which plan you choose. Check your 2026 IRMAA tier →

The Medicare Advantage Open Enrollment Period (Jan 1–Mar 31)

If you're enrolled in a Medicare Advantage plan and miss AEP, you have a second chance: the Medicare Advantage Open Enrollment Period (OEP) runs January 1 through March 31 each year.

You can switch to a different Medicare Advantage plan
You can drop Medicare Advantage and return to Original Medicare (with a Part D plan)
You cannot use OEP to switch from Original Medicare to Medicare Advantage — that requires AEP or a Special Enrollment Period
Changes during OEP take effect the first day of the following month (not January 1)

Special Enrollment Periods (SEPs): when you don't have to wait

Certain life events give you a Special Enrollment Period outside AEP:

Qualifying event	SEP window
Losing employer or union coverage	8 months from when coverage ends
Moving out of your plan's service area	2 months
Moving to or from a nursing home or long-term care facility	2 months
Leaving Medicare Advantage due to plan contract termination	Variable
Achieving Extra Help / Low Income Subsidy (LIS) status	Once per quarter

If you retired mid-year and are transitioning from employer coverage, your SEP for Part B and Part D is 8 months from when your employer coverage ends. See the full Medicare enrollment guide →

AEP plan-comparison checklist

Before making any changes during AEP, work through this checklist:

Step 1: Review your Annual Notice of Change (ANOC)

Your current Medicare Advantage or Part D plan was required to mail you an ANOC by September 30. It lists every change to your plan for 2027: premiums, deductibles, copays, prior authorization requirements, and any drugs removed from or added to the formulary.

What to flag:

Is your plan's premium increasing significantly?
Did your regular medications move to a higher tier (higher copay) or get removed from the formulary?
Did any of your regular doctors leave the network?
Did prior authorization requirements expand for services you use?
Did the out-of-pocket maximum change?

Step 2: Run Medicare Plan Finder for your specific drugs

Go to medicare.gov/plan-compare, enter your zip code and medications (drug name + dosage + quantity), and compare your current plan's estimated annual cost to alternatives. The comparison includes premium + deductible + copays across all plans in your area.

Key number to compare: Total annual drug cost — not just monthly premium. A plan with a $0 premium but a $615 deductible and high copays often costs more than a plan with a $30 premium and lower cost-sharing.

Step 3: For Medicare Advantage — check the provider network for 2027

Networks change January 1. Even if you're staying with the same insurer, confirm your primary care doctor, key specialists, and preferred hospitals are still in-network for 2027. Call the plan or check the plan's online provider directory — not the insurer's general directory.

Step 4: Assess whether to switch between Original Medicare and Medicare Advantage

This is the highest-stakes decision. Use the framework below:

Your situation	Lean toward
Travel frequently or spend time in multiple states	Original Medicare + Medigap (nationwide acceptance)
Managing multiple chronic conditions, frequent specialist visits	Original Medicare + Medigap (no network restrictions, no prior auth)
Healthy, mostly routine care, prefer lower monthly premium	Medicare Advantage (lower premium, extra benefits)
Need dental, vision, or hearing coverage	Medicare Advantage (many plans include extras)
Have a specific specialist or hospital you're unwilling to lose	Verify network before switching — MA networks restrict access
High income with IRMAA exposure	Either path — IRMAA applies to Part B regardless

Step 5: If switching from MA → Original Medicare, check Medigap first

Before dropping Medicare Advantage, contact 2–3 Medigap insurers to confirm you can get coverage and at what price. If you're in a state with guaranteed-issue protections (CT, ME, MA, MN, NY, WA have some year-round protections), you have more flexibility. In most other states, do not drop MA until you have a confirmed Medigap acceptance in hand.

Medicare decisions interact with your broader retirement income plan.

Your IRMAA tier is driven by income — Roth conversions, RMDs, and capital gains harvesting all affect your Part B and Part D surcharges. A retirement income specialist can review your projected income and help you manage IRMAA before the 2-year lookback locks it in.

Talk to a retirement specialist →

How AEP interacts with your retirement income plan

Medicare choices don't exist in isolation. Three financial planning connections worth knowing:

IRMAA and income management

Your 2027 Part B and Part D premiums will be based on your 2025 MAGI (two-year lookback). If you had a one-time income spike in 2025 — a large Roth conversion, home sale, or RMD bunching — you may be paying IRMAA surcharges in 2027 that you can appeal via Form SSA-44 if a qualifying life event (retirement, work reduction, etc.) has since reduced your income. See how to appeal IRMAA →

Part D OOP cap and Roth planning

If you're on expensive specialty drugs, the $2,100 Part D OOP cap limits your downside drug cost risk — which may factor into how much LTC self-insurance buffer you need and whether purchasing a standalone LTC policy makes sense at your premium price point. See long-term care planning →

Medigap premiums and retirement spending

Plan G premiums range from roughly $150–$250/month at 65 and increase with age. Over a 20-year retirement, that's $36,000–$60,000 in premium payments (nominal). Running a spending plan that includes healthcare cost escalation helps stress-test your withdrawal rate. See retirement spending plan →

Sources

Inflation Reduction Act of 2022, Pub. L. 117-169 — Part D $2,000 OOP cap (indexed; $2,100 for 2026). cms.gov — 2026 Medicare Parts B Premiums and Deductibles
CMS — 2026 Medicare Part D standard benefit parameters: $615 deductible, $38.99 base beneficiary premium. cms.gov — Prescription Drug Coverage General Information
CMS — 2026 Part D IRMAA surcharge tables: income thresholds from 2024 MAGI, surcharges $13.70–$85.80/month. IRS Rev. Proc. 2025-67 / CMS IRMAA tables
Medicare.gov — Annual Enrollment Period overview, OEP rules, and SEP qualifying events. medicare.gov — Joining a Medicare plan

Values verified as of October 2026. Medicare rules change annually; verify current plan details at medicare.gov or with a licensed Medicare counselor.