If you’re already on Medicare, mark your calendar: the Annual Enrollment Period (AEP) runs from October 15 to December 7, 2026, and it’s the one window each year when you can make a completely fresh choice about your coverage for 2027. Whether you keep your current plan or switch, this guide walks through what’s changing, how to tell if a review is worth your time, and how to compare options without getting lost in the process.
What Is the Medicare Annual Enrollment Period (AEP)?
AEP is the annual window during which anyone enrolled in Medicare can change their coverage for the upcoming plan year. It’s separate from, and much broader than, the Initial Enrollment Period that applies when you first become eligible for Medicare around your 65th birthday.
Who AEP applies to (vs. Initial Enrollment). Initial Enrollment is a one-time, seven-month window built around the month you turn 65 — it’s for people who are new to Medicare. AEP, by contrast, applies every year to anyone already enrolled, whether you’ve had the same plan for one year or fifteen. If you’re approaching 65 and haven’t enrolled in Medicare yet, our Medicare enrollment timeline for turning 65 guide covers that separate process in detail.
What you can — and can’t — change during AEP. During this window you can:
- Switch from Original Medicare to a Medicare Advantage plan, or vice versa
- Switch from one Medicare Advantage plan to another
- Join, switch, or drop a Part D prescription drug plan
- Switch from one Part D plan to another
Medicare Supplement (Medigap) changes work a little differently — you can apply to switch a Medigap policy at any time, but outside your one-time Medigap Open Enrollment Period, the carrier can ask medical underwriting questions and may decline coverage or charge more based on your health.
2027 AEP Key Dates
- October 15, 2026: AEP opens. You can start comparing and submitting plan changes.
- December 7, 2026: AEP closes. Any change you make must be submitted by this date.
- January 1, 2027: Coverage under your new selection (or your unchanged plan) takes effect.
There’s no advantage to waiting until the last week — carriers and licensed agents both get busy as December 7 approaches, and starting earlier gives you more time to make sure a new plan actually fits your prescriptions and providers before you commit.
What’s Changing for 2027 Medicare Plans
Medicare plan costs, formularies, and provider networks are reset every year, which is exactly why AEP exists. A few things worth knowing heading into 2027:
Medicare Advantage payments are increasing industry-wide. CMS’s final 2027 rate announcement set Medicare Advantage plan payments about 2.48% higher nationally (roughly $13 billion in aggregate), rising to close to 5% once risk-score trends are factored in. In practice, a broad payment increase like this tends to support plan stability and benefit offerings, though what it means for any specific plan’s premium, copays, or extra benefits is still a plan-by-plan decision each carrier makes.
Official 2027 Part B premium and deductible amounts are typically announced by CMS in November, shortly after AEP opens. Any number you see published before then is a projection, not a final figure — it’s worth checking the official amount once it’s released rather than budgeting around an early estimate.
Your current plan can change even if you don’t. Most Medicare Advantage and Part D plans renew automatically if you take no action, but that “same” plan can carry a different premium, a different drug formulary, or a narrower provider network in 2027 than it had in 2026. This is the single most common reason people are unexpectedly surprised by a bill or a denied claim in January — not because they switched plans, but because their unchanged plan changed around them.
The Part D annual out-of-pocket cap continues into 2027. Since 2025, the Inflation Reduction Act has capped what Medicare beneficiaries pay out-of-pocket for covered prescription drugs each year — once you hit that cap, your covered drug costs for the rest of the year are $0. The exact dollar cap adjusts slightly each year, but the structure itself carries into 2027, and it’s one of the more meaningful changes to Part D in years for anyone on multiple or high-cost medications. It’s also part of why comparing Part D plans by premium alone doesn’t tell the whole story — two plans with different premiums can lead you to the annual cap at very different total costs depending on their formulary tiers.
Plan benefits and star ratings shift every year. Extra benefits that drew you to a Medicare Advantage plan — dental, vision, a fitness allowance, an over-the-counter card — are set by the carrier annually and are not guaranteed to carry over unchanged. A plan’s star rating (Medicare’s 1-to-5 quality score) can also move up or down year to year, which affects both the extras a plan can offer and, for 5-star plans, a special year-round enrollment opportunity outside AEP.
Should You Switch Plans This Year? A Simple Checklist
You don’t need to switch plans every year, but AEP is the right moment to at least check these three things:
- Check your prescription formulary. Log in to your plan’s portal or check the plan’s 2027 formulary document for every medication you take regularly. A drug moving to a higher cost tier — or off the formulary entirely — is one of the most common (and most expensive) surprises.
- Check your doctors and network. Confirm your primary care provider, specialists, and preferred hospital are still in-network for 2027, especially if you’re on a Medicare Advantage HMO or PPO plan.
- Compare total annual cost, not just the premium. A lower monthly premium can still add up to more out-of-pocket cost over the year once you factor in deductibles, copays, and coinsurance for the care you actually use.
If all three check out, staying put is a perfectly reasonable choice. If any one of them raises a flag, it’s worth spending 15 minutes comparing alternatives before December 7.
Medicare Advantage vs. Medicare Supplement: Which to Review
If you’re on a Medicare Advantage plan, AEP is your primary opportunity each year to switch plans or move back to Original Medicare — this is the review that matters most for you every fall.
If you’re on Original Medicare with a Medicare Supplement (Medigap) policy, your Medigap coverage itself doesn’t have an annual contract year the way Medicare Advantage does, so AEP’s relevance to you is mostly about your standalone Part D drug plan, which does reset every year and is worth checking on the same formulary and cost basis described above. That said, some people on Medigap use AEP as a natural annual checkpoint to ask whether a different Medigap plan letter, or a Medicare Advantage plan altogether, might fit their situation better than it did when they first enrolled — switching Medigap plans outside your protected enrollment window just means being aware that medical underwriting may apply.
How to Compare Plans Without Getting Overwhelmed
Using Medicare.gov Plan Finder. Medicare’s official Plan Finder tool lets you enter your medications and pharmacy to see estimated costs across every plan available in your county. It’s a solid starting point, but it can also return dozens of options with little guidance on which differences actually matter for your situation, especially once you start weighing formulary tiers against network breadth against extra benefits.
Why a licensed, multi-carrier agent can save you time. A licensed agent who works with multiple carriers can narrow that list down to the handful of plans that genuinely fit your prescriptions, providers, and budget — and walk you through the tradeoffs in plain language rather than a spreadsheet of options. A good multi-carrier comparison typically covers:
- Whether your current medications are on each plan’s formulary, and at what tier
- Whether your doctors, specialists, and preferred hospital are in-network
- Total estimated annual cost across premium, deductible, and expected copays — not just the monthly premium
- Which extra benefits (dental, vision, fitness, OTC allowance) each plan actually offers for 2027
Because agents are compensated by the carrier rather than by the person they’re helping, this kind of consultation is free to you, and a multi-carrier agent has no incentive to steer you toward one company’s plan over another.
Common AEP Mistakes to Avoid
- Assuming “no letter means no change.” Carriers are required to send an Annual Notice of Change, but it’s easy to skim past. If you can’t find it, log in to your plan’s portal directly rather than assuming nothing changed.
- Comparing plans by premium alone. A $0-premium plan with a narrow formulary can cost far more over a year than a plan with a modest premium and better drug coverage for your specific medications.
- Waiting until the first week of December. Licensed agents and plan call centers both see their heaviest call volume in the final days before December 7. Starting your review in October or early November gives you room to actually compare, rather than rushing a decision.
- Confusing AEP with the Medicare Advantage Open Enrollment Period. The two windows allow different things and serve different audiences — see the FAQ below for the distinction.
What Happens If You Miss the December 7 Deadline
If you don’t make a change by December 7, your current plan simply continues (or renews) into 2027 with whatever updates it has for the new year. Outside of AEP, most people can’t make further plan changes until the next AEP the following fall, with a few narrow exceptions:
- The separate Medicare Advantage Open Enrollment Period (January 1 – March 31) lets people already in a Medicare Advantage plan make one additional switch.
- A Special Enrollment Period may open outside AEP if you experience a qualifying life event, such as moving out of your plan’s service area.
Missing December 7 isn’t the end of the world, but it does mean living with whatever your current plan looks like for a full year — which is exactly why reviewing before the deadline is worth the time.
Get Free Help Comparing Your 2027 Medicare Options
Between the formulary check, the network check, and comparing total annual cost across plans, a thorough AEP review takes real time — time a licensed agent who works with multiple carriers can save you. All Solution Plus is a licensed insurance agency serving clients in 48 states, and a consultation to compare your 2027 Medicare Advantage, Medicare Supplement, or Part D options costs nothing.
Talk to a licensed Medicare agent before December 7 →
Frequently Asked Questions
What is the difference between AEP and the Medicare Advantage Open Enrollment Period?
AEP (October 15 – December 7) lets anyone on Medicare make any plan change for the next year. The separate Medicare Advantage Open Enrollment Period (January 1 – March 31) is a one-time do-over limited to people already in a Medicare Advantage plan.
Will my Medicare Advantage plan automatically renew if I do nothing during AEP?
In most cases yes, unless your plan is leaving your area, but your premium, drug formulary, and provider network can all change year to year even on the “same” plan.
Can I switch from Medicare Advantage back to Original Medicare during AEP?
Yes — AEP allows switching in any direction between Original Medicare, Medicare Advantage, and Part D plans.
Is there a cost to get help comparing Medicare plans from a licensed agent?
No. Licensed agent consultations are free to the consumer; agents are compensated by the carrier, not the client.
