The Medicare Annual Enrollment Period (AEP) runs October 15 through December 7 every year, and it's the one window most people have to switch Medicare Advantage or Part D plans for the coming year. Thousands of Floridians miss out on better coverage each year by making one of these avoidable mistakes.

Mistake #1: Assuming Your Plan Is Staying the Same

Every fall, Medicare mails an Annual Notice of Change (ANOC) letter explaining how your specific plan is changing for the next year, including premiums, copays, covered drugs, and provider networks. Many people set this letter aside without reading it, then find out in January that their premium went up, a medication moved to a higher tier, or a favorite doctor is no longer in-network. Reading this one letter is the single most effective thing you can do during AEP.

Mistake #2: Not Checking the Provider Network Every Year

Insurance companies renegotiate their provider contracts annually, which means a doctor or hospital that was in-network last year is not guaranteed to be in-network next year. This is especially common in Florida, where some hospital systems have gone out-of-network with major carriers from one year to the next. Always confirm your specific doctors and pharmacy are still covered before re-enrolling in the same plan.

Mistake #3: Ignoring the Drug Formulary

A plan's list of covered medications, and the tier each drug falls into, can change every year even if the plan name stays the same. A medication that was inexpensive last year could jump to a much higher copay tier, or be dropped from the formulary altogether. If you take regular prescriptions, check the updated formulary for the coming year rather than assuming your costs will stay the same.

Mistake #4: Waiting Until the Last Week of AEP

AEP runs for nearly two months, but a large share of enrollment activity happens in the final week before the December 7 deadline. Waiting until the last minute leaves little time to compare plans carefully, get questions answered, or fix a mistake if something goes wrong with the application. Starting your review in October, as soon as your ANOC letter arrives, gives you much more breathing room.

Mistake #5: Not Getting a Second Opinion From a Licensed Agent

Comparing Medicare Advantage and Part D plans on your own means wading through dozens of options, each with different premiums, networks, drug formularies, and extra benefits like dental or transportation. An independent licensed agent can compare plans from multiple carriers side by side, at no cost to you, and flag issues you might not catch on your own, like a network gap or a formulary change.

Remember: You Get a Second Window Too

If you enroll in a Medicare Advantage plan during AEP and find it isn't working out once you start using it, you get one more chance to switch during the Medicare Advantage Open Enrollment Period, which runs January 1 through March 31. It's a smaller safety net, but it's good to know it exists.