Open Enrollment runs October 15 – December 7, 2026. Any change you make takes effect January 1, 2027.
Every fall, millions of older Americans get a short window to review their Medicare coverage. And every year, many of them let it pass without a second look. That is understandable. Medicare is confusing, the mail piles up, and the phone keeps ringing with sales calls. But skipping this window can quietly cost you hundreds of dollars next year, or leave you with a plan that no longer covers your doctor.
At our adult day care center in New York, we see this every fall. Members bring in thick envelopes they have not opened, or tell us their pharmacy suddenly charged more in January and they do not know why. Most of these problems come from a handful of common mistakes. Here are the seven we see most often, and how to avoid them.
Why 2027 deserves extra attention
This is not a year to put your plan on autopilot. Several changes take effect on January 1, 2027:
- Higher drug cost limits. The yearly cap on out-of-pocket costs for Part D prescription drugs rises to $2,400 (up from $2,100), and the standard deductible rises from $615 to $700.
- A temporary Part D premium subsidy is ending, which may push some drug plan premiums higher.
- New negotiated prices for 15 drugs, including Ozempic, Wegovy and Rybelsus, along with medications such as Trelegy Ellipta, Xtandi, Ibrance, Linzess, Breo Ellipta, Tradjenta, Xifaxan and Otezla.
- Some Medicare Advantage plans are leaving certain areas or cutting extra benefits such as dental coverage.
Any one of these could change what you pay next year. That is exactly why the mistakes below matter.
Mistake #1: Assuming your plan will stay the same
Your plan renews automatically, so it is easy to think nothing has changed. But insurance companies can change premiums, copays, which drugs they cover, and which doctors are in network every single year. These changes are listed in the Annual Notice of Change (ANOC) your plan mailed in September.
What to do: Find that letter (it often looks like junk mail) and read the summary page. If you cannot find it, call the phone number on the back of your insurance card and ask for it.
Mistake #2: Not checking your medications against the new drug list
Each plan has a list of covered drugs, called a formulary. A medication you take every day can move to a more expensive tier, require prior approval, or be dropped altogether.
What to do: Write down every prescription you take, with the dose. Enter them into the Plan Finder at Medicare.gov. It will show you the estimated total yearly cost for each plan in your area, not just the monthly premium.
Mistake #3: Choosing a plan by premium alone
A $0 premium plan sounds like a great deal. But a low premium can come with higher copays, a higher deductible, or a smaller network of doctors. The plan that looks cheapest in October can end up being the most expensive by December.
What to do: Compare the total estimated yearly cost: premium plus drug costs plus the copays you are likely to pay for your usual doctor visits.
Mistake #4: Not confirming your doctors and pharmacy are still in network
This applies especially to Medicare Advantage plans, which usually limit you to a network. Doctors and hospitals can leave a network from one year to the next. Pharmacies can switch between "preferred" and "standard," which changes your copay.
What to do: Call your main doctors' offices and ask, "Will you accept my plan in 2027?" Then check that your regular pharmacy is a preferred pharmacy for the plan you choose.
Mistake #5: Waiting until the last week
December 7 comes fast, especially with the holidays. Help lines get crowded, appointments with counselors fill up, and rushed decisions lead to errors.
What to do: Pick one afternoon in early November and block it off for Medicare. Have your insurance card, your medication list and your doctors' names ready.
Mistake #6: Trusting unsolicited calls and "Medicare representatives"
Open Enrollment is peak season for scams and aggressive sales calls. Medicare does not call you out of the blue to sell you a plan or to ask for your Medicare number. Callers who say you will "lose your benefits" unless you act today are a red flag.
What to do: Never give your Medicare number, Social Security number or bank details to someone who contacted you first. Hang up and call 1-800-MEDICARE directly if you are unsure.
Mistake #7: Not knowing you have free, unbiased help
Many seniors think their only options are figuring it out alone or talking to a commissioned salesperson. There is a third option. Every state runs a State Health Insurance Assistance Program (SHIP) that offers free, one-on-one counseling from trained volunteers who do not sell insurance.
What to do: Visit shiphelp.org to find the program in your state. Adult children helping a parent can sit in on the appointment too.
Missed the deadline? You may still have options
If you are already in a Medicare Advantage plan, there is a second chance from January 1 to March 31, when you can switch to another Medicare Advantage plan or return to Original Medicare. Certain life events, such as moving, can also open a Special Enrollment Period. But the simplest path is to make a good decision before December 7.
A simple checklist for this week
- Find your Annual Notice of Change letter
- Write down all medications and doses
- List your doctors and your pharmacy
- Compare plans on the Medicare.gov Plan Finder
- Book a free SHIP counseling session if you feel unsure
- Make your choice well before December 7
Medicare decisions can feel overwhelming, but you do not have to make them alone. Asking for help is not a weakness. It is one of the smartest things you can do to protect your health and your budget.
This article is for general information only and is not insurance or legal advice. Plan details vary by location. Always confirm costs and coverage with Medicare.gov, 1-800-MEDICARE, or your state's SHIP counselor.