Medicare AEP Ends December 7: What You Can and Can't Change

Why December 7 matters

The Annual Enrollment Period, usually called AEP, runs every year from October 15 to December 7. According to Medicare.gov, any coverage change you make during that window takes effect on January 1. Your plan for next year is not decided by what you do in January; it is decided by what you submit by the December 7 deadline, which is about six weeks away from the Wednesday, October 28 publication of this issue. If you do nothing, you generally stay in your current coverage, and your current plan may have changed its premium, drug list, doctors in its network, or copays for 2027. Plans send an Annual Notice of Change in the fall explaining those changes, so open it. Think of AEP as the one yearly chance to compare what your plan will do next year against what you actually need. This issue walks through what you can change, what you cannot, and how to check your own plan.

What you can change during AEP

Medicare.gov lists three main moves you can make during AEP. First, you can switch from Original Medicare to a Medicare Advantage plan, or go back from Medicare Advantage to Original Medicare. Second, if you already have Medicare Advantage, you can change to a different Medicare Advantage plan. Third, you can join, switch, or drop a Part D prescription drug plan. Each change you make replaces what you have, so the order matters. If you leave Medicare Advantage for Original Medicare, for example, you will usually want to add a stand-alone Part D plan at the same time so you are not left without drug coverage. Medigap, the supplemental insurance that works with Original Medicare, is different: AEP does not guarantee you can buy one, and insurers in many states may ask health questions. Medicare.gov covers Medigap in its own guidance, so check the rules for your state before dropping a Medicare Advantage plan you might want to return to.

What AEP does not do

AEP is broad, but it is not a free do-over for every decision. The Medicare Advantage Open Enrollment Period, which runs January 1 to March 31, is a separate and more limited window, according to CMS. It applies only to people who are already in a Medicare Advantage plan. It does not let someone in Original Medicare switch into Medicare Advantage, and it does not provide a second full shopping season. So the January window is a safety net for people who joined or stayed in a Medicare Advantage plan and find it does not work, not a reason to put off your decision. A change you try to make after December 7 generally needs to fit a special enrollment situation, and the facts of your situation decide whether you qualify. Your State Health Insurance Assistance Program, known as SHIP, can tell you whether you do. Free local counselors are listed at shiphelp.org, the SHIP National Technical Assistance Center site.

A worked example: comparing two plans

Here is a worked example using made-up numbers. Maria takes two brand-name drugs. This year her plan costs $30 a month in premium, which is $360 a year, plus copays of $45 and $60 a month for her drugs. Those copays add up to $105 a month, or $1,260 a year, so her total is $1,620. Her Annual Notice of Change says that next year her premium rises to $45 a month, or $540, and one drug moves to a higher tier with a $90 copay. Her two copays become $135 a month, or $1,620 a year, so staying put costs $2,160. A different plan charges $55 a month, or $660, with copays of $40 and $50. Those copays total $90 a month, or $1,080 a year, so that plan costs $1,740. The difference is $420. The plan with the higher premium came out cheaper. Add premiums and expected drug costs together, then confirm her pharmacy and doctors are covered before she switches.

What people get wrong

Several mistakes cost people money every year. The first is assuming last year's plan is still the same plan. Premiums, drug tiers, pharmacy networks, and provider networks can all change, which is why the Annual Notice of Change deserves a read. The second is comparing premiums alone, which the example above shows can mislead. The third is skipping the drug list check: a medication that is covered but placed on a higher tier can cost far more. Ask the plan which tier each of your drugs sits on. The fourth is dropping Medicare Advantage for Original Medicare without a plan for supplemental coverage, because Medigap approval is not guaranteed in many states. The fifth is waiting until the last week. Anything submitted after December 7 generally misses the window. Finally, be careful with unsolicited calls and offers. HHS Office of Inspector General guidance says to report suspected Medicare fraud, and you should not share your Medicare number with a caller you cannot verify.

How to check your own situation

Set aside an hour and gather four things. First, your current plan's Annual Notice of Change, which lists next year's premium, deductible, copays, and drug coverage changes. Second, a list of every medication you take, with dose and the pharmacy you use. Third, the names of your doctors and hospitals. Fourth, your Medicare card and ZIP code, which you will need to compare plans on Medicare.gov's plan finder. Then ask each plan these questions. Is each of my drugs on the formulary, and on which tier? Is my pharmacy in the network? Are my doctors and hospitals in the network? What is the total estimated yearly cost, premiums and drugs together, for each plan? If you want a second set of eyes, a SHIP counselor can walk through the comparison for free. Your one takeaway: before December 7, compare your current plan's 2027 costs against at least one alternative, because what you choose by then is what you will have on January 1.

This newsletter is for general education only and is not legal, financial, or insurance advice. Medicare rules and plan details vary by location and personal circumstances; confirm your options with Medicare.gov, 1-800-MEDICARE, or your State Health Insurance Assistance Program (SHIP). Dollar figures in the worked example are hypothetical.