Medicare's Annual Enrollment Period runs October 15 through December 7. Whatever you pick takes effect January 1. If you already have a Medicare plan, this is your one guaranteed chance all year to change it, and you do not need a reason.
Disclosure: I represent multiple insurance carriers in Idaho and am paid by the carrier when a client enrolls. We do not offer every plan available in your area. Currently we represent 5 organizations which offer 27 products in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options. This article is educational. For advice about your own situation, call me.
First, make sure this is the right window for you
Open Enrollment is for people who already have Medicare and want to change something. It is not how you first get Medicare.
If you are turning 65 and signing up for the first time, your window is different, it is built around your birthday, and the first steps happen at Social Security rather than with me. Here is that process, step by step.
The mistake that costs the most money
It is not picking the wrong plan. It is picking nothing.
If you do nothing between now and December 7, you are automatically re-enrolled in your current plan, at next year's prices, with next year's drug list, and next year's network. People read that as "nothing changes." It is closer to the opposite. The plan changes around you, and doing nothing is how you agree to it.
I am not saying you should switch. Plenty of people look carefully and decide to stay exactly where they are, and that is a fine answer. The point is to look.
The checklist
Find the envelope your plan mailed you in September
It is called the Annual Notice of Change, and every plan has to put it in the mail by September 30. Most people throw it out. It is the single most useful piece of paper you will get all year.
Inside is a table with two columns: what your plan does this year, and what it will do next year. Premium, deductible, copays, drug tiers, network. If something is moving, that table is where it shows up. You do not have to read all forty pages. Read the table.
Check your prescriptions against next year's list
Every drug plan publishes a formulary, which is just the list of drugs it covers and what tier each one sits on. That list is rewritten every year.
A drug that was tier 1 this year can be tier 3 next year, which can mean paying three or four times as much for the identical pill. Sometimes a drug comes off the list entirely. Nobody calls to tell you. It shows up in January at the pharmacy counter.
Check that your doctors are still in the network
If you are on a Medicare Advantage plan, this is the one that bites hardest. Networks change every year, and a clinic that was in-network in December can be out in January.
Do not rely on the plan's online directory alone. They are wrong more often than they should be. Call the clinic and ask whether they are contracted with that specific plan for next year, by name.
See what else is available to you
Your plan changed. So did everybody else's. The plan that was the best fit for you two years ago may not be the best fit now, and the only way to know is to look at them side by side against your actual doctors and your actual medications.
This is the part I do, and it costs you nothing. You can also do it yourself on the Medicare Plan Finder at medicare.gov/plan-compare. It is a solid tool. It just takes patience.
Decide before December 7
December 7 is a wall, not a suggestion. Whatever you are enrolled in on December 8 is what you have on January 1.
Do not wait until the first week of December. That is when everybody calls, and that is when hold times at the carriers go from ten minutes to an hour.
What is actually changing for 2027
A few numbers are already locked in:
- The Part D drug deductible cap goes to $700, up from $615 in 2026. No drug plan is allowed to charge more than that, and plenty charge less or nothing at all.
- The out-of-pocket cap on drugs goes to $2,400, up from $2,100 in 2026. Once your own spending on covered drugs hits that number, your covered drugs cost you nothing for the rest of the calendar year. If you are on expensive medication, this is the most important number on this page.
One number that is not settled yet: the 2027 Part B premium. CMS usually announces it in November. Anyone quoting you a hard figure for it today is guessing, and you should be a little suspicious of where else they are guessing.
If you miss December 7
You are not completely out of options, but your options get thinner.
If you are on a Medicare Advantage plan, there is a second window from January 1 to March 31. You can use it once, to move to a different Advantage plan or to go back to Original Medicare with a drug plan. If you are on Original Medicare, that window does not apply to you.
Outside of those, you need a Special Enrollment Period, which requires a qualifying life event: moving, losing other coverage, qualifying for Medicaid or Extra Help. All the windows are laid out here.
A note for Idaho
Ada County has more plans competing for you than most of the state does, which is good for your options and bad for your afternoon. Canyon, Gem and Boise counties have fewer. If you live outside the Treasure Valley, the plan that looked great in a Boise ad may not even be sold in your county, so always check availability by your actual ZIP code.
Idaho also runs free, unbiased counseling through SHIBA if you would rather talk to somebody with no commission involved at all. That number is 1-800-247-4422, and I will give it to you myself if that is what you want.
The bottom line
Open the envelope. Check your drugs. Check your doctors. Compare. Decide before December 7.
If you want somebody to do the comparing with you, that is what I am here for, and it does not cost you anything. I am local, I am independent, and I am not in a hurry.
About the author: Payton Knudson is a licensed independent Medicare insurance agent in Idaho and the founder of Knudson Insurance Team in Boise. This article is for educational purposes only and does not constitute personalized insurance advice.