The dates, and what they mean
The Medicare Annual Enrollment Period — AEP, sometimes called Medicare open enrollment — runs October 15 through December 7, every single year. The dates don't move. Anything you change during that window takes effect January 1 of the following year.
December 7 is a real deadline, not a soft one. Miss it and, for most people, the next opportunity to change a Medicare Advantage or Part D plan is a full year away — with limited exceptions covered further down this page.
What you can actually change
AEP covers more than most people realize. During the window you can:
- Switch from Original Medicare to a Medicare Advantage plan, or move from Medicare Advantage back to Original Medicare.
- Change from one Medicare Advantage plan to another — a different carrier, a different network, a different benefit package.
- Join a Part D prescription drug plan if you don't have one.
- Switch from one Part D plan to another, which is where most people find their real savings.
- Drop Part D coverage entirely, though be aware this can trigger a late enrollment penalty if you go back later without other creditable drug coverage.
One important exception: Medicare Supplement (Medigap) policies don't follow the AEP calendar. You can apply for a Medigap policy any time of year — but outside your initial guaranteed-issue window, carriers can medically underwrite you, meaning your health history affects whether you're approved and what you pay. That's a different set of rules worth understanding on its own.
The most expensive mistake: doing nothing
If you take no action, your current plan generally renews automatically. That feels safe. It usually isn't.
Medicare plans are re-priced and redesigned every year. Premiums shift. Deductibles move. Drug formularies get reorganized, and a medication that was on a low tier this year can jump to a higher one — or come off the formulary entirely. Provider networks change, and the doctor you've seen for a decade may not be in-network in January. None of this is unusual or improper; it's simply how the plans work. But it means the plan you chose two years ago is not the plan you'll have next year, and auto-renewal means accepting those changes sight unseen.
The people who consistently save money on Medicare aren't the ones who found a perfect plan once. They're the ones who spend an hour each fall checking whether their plan is still the right one.
Your AEP checklist
Work through these in order and the decision gets much simpler:
- 1. Find your ANOC — the notice that arrived in September. Read the summary of changes.
- 2. List your medications — exact names, doses, and how often you take them. This is the single biggest driver of your real annual cost, and guessing at it is where most comparisons go wrong.
- 3. List your doctors and hospitals — including any specialist you'd hate to lose. Network status is checked plan by plan.
- 4. Compare total annual cost, not premium — premium plus deductible plus expected copays. A low-premium plan can easily cost more over a year than one with a monthly premium.
- 5. Check the extras that matter to you — dental, vision, hearing, transportation, over-the-counter allowance. These vary widely and are often where plans genuinely differ.
- 6. Decide before Thanksgiving — the first week of December is the busiest of the year for everyone in this business, and rushing a decision is how mistakes happen.
Want us to run your comparison this fall?
We'll check your exact drug list and doctors against every plan available in your county — free, and with no obligation to change anything.
Get on the priority review listOther enrollment windows worth knowing
AEP is the big one, but it isn't the only one:
| Window | When | Who it's for |
|---|---|---|
| Annual Enrollment Period (AEP) | Oct 15 – Dec 7 | Everyone with Medicare |
| Initial Enrollment Period (IEP) | 7 months around your 65th birthday | People newly eligible for Medicare |
| Medicare Advantage Open Enrollment | Jan 1 – Mar 31 | People already in a Medicare Advantage plan |
| Special Enrollment Periods (SEP) | Varies by event | Moving, losing coverage, qualifying for Medicaid or Extra Help |
If you have both Medicare and Medicaid, you likely have more flexibility than the standard calendar allows — see our Medicaid and dual eligible page. And if you're approaching 65 for the first time, your Initial Enrollment Period matters more than AEP right now; our post on when you can switch Medicare plans walks through the timing.
How Honorbrook helps during AEP
Our approach during enrollment season is deliberately unglamorous: we take your actual medication list and your actual doctors, run them against every plan available in your county, and show you the total annual cost of each — not the premium, the real number. Then we tell you what we'd do in your position, including when that means staying exactly where you are. A meaningful share of the reviews we run end with "your plan is still the right one," and we'd rather say that than manufacture a reason to switch you.
Our help costs nothing. Carriers pay agent commissions, and by law your premium is identical whether you enroll through us, directly with the carrier, or on Medicare.gov. We're independent and licensed in 11 states, so we compare across carriers rather than representing one. And we answer the phone in January, which is when questions actually come up.