Medicare open enrollment runs from October 15 to December 7, 2026, and whatever you pick starts on January 1, 2027. If you or someone you love is on Medicare, those seven weeks are the one stretch of the year when the plan, and the bill that comes with it, can change on purpose instead of by surprise.
I’m not on Medicare. My mom is. Last fall she put a thick envelope from her plan on my kitchen table and said, “I think this says my costs are going up, but I can’t tell by how much.” I’m the person in my family who turns paperwork into budget lines, so that became my job.
This post is what I wish I’d had that night: the real dates, what you’re allowed to change, the official cost numbers (with the year next to each one), and how I turn all of it into monthly lines and sinking funds. I’m not a licensed advisor and I won’t tell you which plan to pick. I’ll show you how to see the money clearly so the choice gets easier.
Medicare open enrollment dates for 2026, plus the window after it
There are two yearly windows people mix up, and my mom mixed them up too. Side by side, from Medicare’s own enrollment fact sheet:
- Open Enrollment: October 15 to December 7. This is the one most people mean. Some folks call it the Medicare annual enrollment period, or AEP. Changes take effect January 1, and the plan has to receive your request by December 7.
- Medicare Advantage Open Enrollment: January 1 to March 31. Only for people already in a Medicare Advantage Plan. Changes start the first day of the month after the plan gets your request.
Medicare’s yearly review guide also flags October 1 as the “get ready” date. That’s roughly when your plan’s Annual Notice of Change shows up, the letter explaining how your costs and benefits will shift next year.
In our house, that letter sat unopened for nine days. Don’t be us.
What you can change between October 15 and December 7
The Medicare annual enrollment period is the wide-open window. According to Medicare.gov’s page on joining a plan, during these weeks you can:
- Join, drop, or switch Medicare Advantage Plans, with or without drug coverage.
- Move from Original Medicare to a Medicare Advantage Plan, or the other way around.
- Join, drop, or switch a stand-alone Medicare drug plan (Part D) if you’re in Original Medicare.
What calmed my mom down: if you review your options and you’re happy, you don’t have to do anything. Medicare’s guide says your coverage continues automatically.
Doing nothing is allowed. Doing nothing without reading the letter is how people get blindsided in January, because costs and covered drugs can change every year even when the plan name stays the same.
One more thing that made me slow down. If you have a Medigap (Medicare Supplement) policy and switch to Medicare Advantage, Medicare warns you may not be able to get that same Medigap policy back later, depending on your state’s rules. I’d make that phone call before December 7.
The Medicare Advantage open enrollment period, January 1 to March 31
I call this the do-over window, with a smaller menu. It only applies if you’re already in a Medicare Advantage Plan. New members get a version too: after first-time enrollment Medicare gives you three months, counted from when you have both Parts A and B.
During the Medicare Advantage open enrollment period you can:
- Switch to a different Medicare Advantage Plan, with or without drug coverage.
- Drop your Medicare Advantage Plan and go back to Original Medicare, then join a separate drug plan.
You can’t use it to move from Original Medicare into Medicare Advantage, and you can’t switch from one stand-alone drug plan to another. Medicare’s fact sheet is also clear that you can only make one change during this window each year.
It’s a safety net, a small one. I’d still treat the fall window as the real decision and January as the backup.
My mom’s words after we finished: “So the scary envelope was mostly a calendar.” Pretty much, Mom.
What Medicare costs right now, line by line
Now the budget part. Every figure below comes from Medicare.gov or CMS, and I’m labeling the year on purpose, because the 2027 Part A and Part B numbers weren’t published yet when I wrote this (early October 2026). Last year CMS announced them on November 14.
- Part B premium: $202.90 a month (2026). That’s the standard amount. People with higher incomes pay more. It went up $17.90 from $185.00 in 2025, so I plan on another increase for 2027.
- Part B deductible: $283 a year (2026). After that, you usually pay 20% of the Medicare-approved cost for Part B services.
- Part A hospital deductible: $1,736 per benefit period (2026). Most people pay $0 a month for Part A itself. Those who don’t qualify for premium-free Part A pay $311 or $565 a month.
- Part D out-of-pocket cap: $2,400 in 2027 (it’s $2,100 in 2026). Once your spending on covered drugs hits that cap, you’re done paying for covered Part D drugs for the year.
- Part D deductible: no plan can charge more than $700 in 2027 ($615 in 2026), and some plans have no deductible at all.
CMS also published projections for 2027 plan premiums in late September 2026. The average stand-alone drug plan premium is projected at about $36 a month, and the weighted average Medicare Advantage premium at $12.00 a month. Averages hide a huge range, so treat them as a sanity check only.
If you’ve read my breakdown of the average health insurance cost per month for people under 65, you’ll notice the shape is the same. A fixed premium, a deductible, then a percentage. Medicare just has more letters.
How I turn Medicare costs into monthly sinking funds
This is the part I’m good at. I took my mom’s letter and a legal pad, and we did this in about 40 minutes, a week before Medicare open enrollment started.
- Separate the monthly bills from the “someday” bills. Premiums are monthly and predictable. Deductibles and drug costs show up in lumps.
- Put every premium on the regular monthly budget. Part B, plus any drug plan or Medicare Advantage plan premium. These get paid like rent.
- Divide each yearly deductible by 12. The $283 Part B deductible becomes $23.58 a month. That money goes into a medical sinking fund, not the checking account.
- Decide how much of a bad year you want covered. The $1,736 hospital deductible works out to $144.67 a month if you fund it over a year. Some families fund it fully, some fund half and lean on an emergency fund.
- Use the drug cap as your ceiling. In 2027, the most anyone pays for covered Part D drugs is $2,400. That’s $200 a month at worst, which made the drug line feel finite for the first time.
- Write the date the new numbers drop on the calendar. When CMS posts the 2027 Part B figures, swap them in and re-divide.
If you already keep sinking funds, this slots right into your sinking fund categories as one more line. I called my mom’s “Medicare cushion,” and she liked that better than “medical.”
Cozy tip: Before December 7, write down one number: the total monthly amount for premiums plus the deductible divide-by-12. Even if the plan doesn’t change, knowing that number makes January feel a lot less scary. My free budget printable has a blank sinking fund page that works for this.
A worked example: one year of Medicare as a budget
This is a worked example, not anyone’s real medical bills. In this example, a person has Original Medicare, premium-free Part A, the standard Part B premium, and a stand-alone drug plan priced at the CMS projected 2027 average. I show a steady year and a rough year side by side.
| Budget line | Official figure (year) | Steady year, per month | Rough year, per month |
|---|---|---|---|
| Part B premium | $202.90/month (2026) | $202.90 | $202.90 |
| Part B deductible | $283/year (2026) | $23.58 | $23.58 |
| Drug plan premium | About $36/month (2027 projected average) | $36.00 | $36.00 |
| Drug costs | $700 max deductible / $2,400 cap (2027) | $58.33 | $200.00 |
| Hospital stay | $1,736 Part A deductible (2026) | $0.00 | $144.67 |
| Total | Monthly budget line | $320.81 | $607.15 |
Over twelve months, that’s $3,849.72 in the steady version and $7,285.80 in the rough one. The gap is about $3,436, and that gap is what a sinking fund is for.
The table leaves out the 20% you usually pay on Part B services after the deductible, because that depends on how many visits and tests a person has. I’d add a line for it once you’ve looked at last year’s statements.
How to review your plan during Medicare open enrollment without getting sold to
Around October the mailbox and the TV fill up. Medicare’s own guide reminds people that Medicare.gov, the “Medicare & You” handbook, and 1-800-MEDICARE are the official, unbiased sources. Everything else is somebody’s marketing.
We did my mom’s review in this order.
- Read the Annual Notice of Change first. Circle any change to the premium, deductible, or drug list.
- Use the Medicare Plan Finder at Medicare.gov/plan-compare. CMS says it lets you compare plans’ premiums, costs, and benefits, and you can enter your actual drugs and pharmacy.
- Check your doctors. The Plan Finder lets you search whether a provider is in a plan’s network.
- Call your SHIP. Every state has a State Health Insurance Assistance Program with free, unbiased one-on-one counseling. Find yours at shiphelp.org. This was the single most useful call we made.
- Ask about help paying. Medicare Savings Programs and Extra Help exist for people with limited income and resources.
The first year, I tried to do the comparison myself in a spreadsheet and got lost around drug tier pricing. The SHIP counselor untangled it in one call. Ask for help early. The CMS fact sheet on 2026 premiums and deductibles is also worth a bookmark so you can see the official numbers without a sales pitch attached.
My roundup of budgeting statistics has household spending numbers with sources linked, and the rest of my budgeting guides cover the monthly system this plugs into.
Common mistakes during Medicare open enrollment
- Waiting for the January do-over. The January to March window only helps people already in Medicare Advantage, and it allows one change. The fall window is the real one.
- Budgeting only for the premium. The $202.90 Part B premium (2026) is the predictable part. Deductibles and drug costs are what break a budget, so give them their own sinking fund.
- Assuming nothing changed because the plan name didn’t. Costs, drug lists, and networks can change every year. Read the Annual Notice of Change even if you plan to stay put.
Frequently Asked Questions
When is Medicare open enrollment for 2027 coverage?
It runs from October 15 to December 7, 2026. If you make a change, your new coverage starts January 1, 2027, and the plan has to receive your request by December 7.
What is the Medicare Advantage open enrollment period?
It runs January 1 to March 31 for people already in a Medicare Advantage Plan. You can switch to another Medicare Advantage Plan or go back to Original Medicare and join a drug plan. You can only make one change during this window each year.
Do I have to do anything during open enrollment if I like my plan?
No. Medicare says if you’ve reviewed your options and you’re happy, your coverage continues automatically. It’s still worth reading your plan’s Annual Notice of Change, because costs and covered drugs can change from year to year.
How much is the Medicare Part B premium?
The standard Part B premium is $202.90 a month in 2026, with a $283 yearly deductible. CMS hadn’t published the 2027 amounts in early October 2026. Last year it announced them in mid-November.
Where can I get free help comparing Medicare plans?
Your State Health Insurance Assistance Program (SHIP) offers free, unbiased counseling; find your local office at shiphelp.org. You can also call 1-800-MEDICARE (1-800-633-4227) or compare plans yourself with the Plan Finder at Medicare.gov.
If you do one thing this week, open the Annual Notice of Change and write the new premium and deductible on a sticky note. Then divide the deductible by 12. That one small number is how my mom went from dreading the envelope to filing it in a folder labeled “handled.”
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