By Qamar S, 15 years in US medical billing · Last reviewed September 28, 2026
Medicare Open Enrollment for 2027 coverage runs from October 15 to December 7, 2026. During this window you can switch Medicare Advantage plans, move between Medicare Advantage and Original Medicare, and join, switch or drop a Part D drug plan. Your new coverage starts January 1, 2027.
Do nothing, and most plans renew automatically, even if the premium, deductible, drug list or network changed. The only way to know is to read your Annual Notice of Change (ANOC) and compare plans before December 7.
What you can do during Open Enrollment
- Switch from Original Medicare to a Medicare Advantage plan
- Switch from Medicare Advantage back to Original Medicare
- Switch from one Medicare Advantage plan to another
- Join, switch or drop a Part D drug plan
What Open Enrollment doesn’t cover
- Medigap. Open Enrollment doesn’t give you a right to buy a Medigap policy. In most states insurers can ask health questions. See switching from Medicare Advantage to Medigap.
- Marketplace (ACA) plans. If you’re under 65, HealthCare.gov Open Enrollment for 2027 starts November 1. See our Open Enrollment 2027 guide.
Key dates
| Date | What happens |
|---|---|
| By September 30, 2026 | Your plan mails your Annual Notice of Change (ANOC) |
| Early October | Plan Finder shows 2027 plans; non-renewal letters arrive if your plan is ending |
| October 15, 2026 | Open Enrollment starts |
| December 7, 2026 | Last day to make changes |
| January 1, 2027 | New coverage starts |
| January 1 to March 31, 2027 | If you’re in Medicare Advantage, one more chance to switch plans or go to Original Medicare |
Your plan review checklist
- Read your ANOC. Look for changes to the premium, deductible, copays, doctor network and drug list.
- List your drugs with the exact dose and how often you take them.
- Use the Plan Finder at Medicare.gov. Compare the estimated total yearly cost (premium plus drug costs), not just the premium.
- Check your doctors and hospitals are in network for 2027 if you’re in Medicare Advantage.
- Check your pharmacy. Preferred pharmacies can mean much lower copays.
- Look at the out-of-pocket maximum for Medicare Advantage plans.
- Check prior authorization rules for care you use regularly.
- Enroll by December 7 through Medicare.gov, 1-800-MEDICARE or the plan.
What’s different for 2027
The Part D out-of-pocket cap rises to $2,400, plans can charge a deductible of up to $700, and 15 more drugs get negotiated prices. Some Medicare Advantage plans are also leaving. Read the Medicare changes for 2027 and, if you got a non-renewal letter, what to do if your plan is ending.
From 15 years in billing: save a copy of your plan’s 2027 Evidence of Coverage and drug list after you enroll. If a claim is denied next year, those documents are what you, or your doctor’s billing office, will use to appeal.
Avoid Medicare scams
Medicare won’t call you out of the blue to sell a plan or ask for your Medicare number. Hang up on anyone who does, and never give your Medicare number to a caller. Free, unbiased help is available from your State Health Insurance Assistance Program (SHIP) at shiphelp.org or 1-877-839-2675.
Frequently asked questions
When is Medicare Open Enrollment for 2027?
October 15 to December 7, 2026. Changes you make start January 1, 2027.
What happens if I do nothing during Open Enrollment?
Most plans renew automatically, even if the premium, deductible, drug list or network changed. Read your Annual Notice of Change before December 7.
Can I buy Medigap during Medicare Open Enrollment?
Open Enrollment does not give you a right to buy Medigap. In most states insurers can ask health questions unless you have a guaranteed issue right.
Is there another chance to change plans after December 7?
If you are in a Medicare Advantage plan, you can switch plans or go back to Original Medicare once between January 1 and March 31, 2027.
Sources: Medicare.gov: Joining a plan · Medicare.gov: Special Enrollment Periods · Medicare.gov: Plan Finder
This guide is educational and is not legal, financial or insurance advice. MedBillGuide is not connected to Medicare, CMS or any government agency, and we do not sell insurance. See our Disclaimer.