Medicare Open Enrollment 2026: What You Can and Cannot Change This Fall
Medicare open enrollment for 2027 coverage runs from October 15 to December 7, 2026. During that window a person who already has Medicare can switch between Original Medicare and a Medicare Advantage plan, move from one Medicare Advantage plan to another, and, for people in Original Medicare, join, switch or drop a drug plan. Changes take effect on January 1, 2027, and the plan must receive the request by December 7. The window does not open Part B to someone who has not yet signed up. It is also not the one-time Medigap Open Enrollment Period. And it does not change the income-related part of the premium, which Social Security generally sets from the tax return for two years earlier.
- Open enrollment runs October 15 through December 7, 2026, and changes start January 1, 2027 (Centers for Medicare & Medicaid Services, CMS).
- In the window, a person can switch between Original Medicare and Medicare Advantage, change Medicare Advantage plans, and change Part D drug coverage (Medicare.gov).
- CMS says people who want to keep their current coverage generally do not need to re-enroll, and that plan costs and benefits can change from year to year.
- The fall window is not a Part B sign-up period and not the Medigap Open Enrollment Period. Each has its own dates.
- The standard Part B premium is $202.90 a month for 2026. The extra amount higher-income members pay is generally based on a tax return from two years earlier (CMS, Social Security).
What Medicare Open Enrollment Covers
Medicare open enrollment is the yearly window, October 15 through December 7, when a person who already has Medicare can change how they receive it. The federal regulation calls it the annual coordinated election period. The table shows which moves the fall window allows.
| Change | In the October 15 to December 7 window? | Note |
|---|---|---|
| Original Medicare to a Medicare Advantage plan | Yes | Medicare.gov lists it among the fall changes |
| Medicare Advantage plan to Original Medicare | Yes | Medicare.gov notes there are limits on when Medigap can be added |
| One Medicare Advantage plan to another | Yes | With or without drug coverage |
| Join, switch or drop a stand-alone Part D drug plan | Yes, for people in Original Medicare | People in a Medicare Advantage plan generally add or drop drug coverage as part of a plan change |
| First-time Part B sign-up | No | Part B has its own enrollment periods |
| Medigap without medical underwriting | Generally no | Medigap has its own six-month period; some federal and state protections allow it at other times |
Medicare.gov lists three ways to join a plan: select “Enroll” for the plan at Medicare.gov/plan-compare, contact the plan, or call 1-800-MEDICARE (1-800-633-4227). A paper form mailed to the plan has to reach it before the enrollment period ends. For a January 1 start, the plan must get the request by December 7.
What Happens If a Person Does Nothing in Open Enrollment
CMS says people who want to keep their current Medicare coverage generally do not need to re-enroll. The same release notes that plan costs and benefits can change from year to year. Medicare Advantage and Part D plans must tell their members about changes that take effect January 1 at least 15 days before open enrollment begins. That notice is where a household sees what its own plan changes for January.
Plan choice is wide. KFF reports that 35.2 million of the 64.2 million Medicare beneficiaries with both Part A and Part B, or 55%, are enrolled in Medicare Advantage in 2026 (March 2026 data), and that the average beneficiary can choose from 35 Medicare Advantage plans available for general enrollment in 2027, 28 of them with drug coverage (KFF, October 1, 2026).
What Is New for 2027
In its September 28, 2026 release, CMS projected a weighted average monthly Medicare Advantage premium of $12.00 for 2027, down 16.5% from $14.37 in 2026, and an average stand-alone Part D premium of $36, up from $35.09. These are CMS projections and averages across plans. A given plan’s premium can differ, and its Annual Notice of Change shows its own figures. Part B and income-related premiums are published separately for each year, and the Part B figures on this page are the 2026 amounts.
CMS says Medicare.gov has changed since the last open enrollment: users can find and save providers to help compare plans, and, starting in October, can see messages about changes affecting their current plans in 2027 and connect to plan documents such as formularies.
A Short Review List Before December 7
CMS Administrator Dr. Mehmet Oz said CMS urges beneficiaries to use open enrollment to “review their coverage, compare options” and choose the plan that suits their needs and budget. The steps the CMS materials point to are these.
- Read what the plan sends. CMS says people should always review the materials their plans send them, including the Evidence of Coverage and the Annual Notice of Change.
- Check the plan’s providers and drug list. Medicare.gov’s plan comparison tools let people save their providers, and plan documents such as the formulary are linked from Medicare.gov.
- Compare plans at Medicare.gov, or call 1-800-MEDICARE (1-800-633-4227), which CMS says is available 24 hours a day, seven days a week.
- Make the request by December 7. For a January 1 start, the plan must receive it by then.
What Open Enrollment Does Not Change
Part B has its own windows. Fall open enrollment is not how someone signs up for Part B. For someone who becomes eligible at 65, the Initial Enrollment Period lasts seven months, starting three months before a person turns 65 and ending three months after the month the person turns 65. A person who misses it can sign up between January 1 and March 31 each year, though late enrollment penalties may apply. The Part B premium is increased by ten percent for each full twelve months a person could have had Part B but did not enroll. Medicare.gov says the penalty generally does not apply to people who qualify for a Special Enrollment Period or enroll in a Medicare Savings Program.
Medigap has its own six-month window. Under federal law there is a six-month Medigap Open Enrollment Period. It starts the first month a person has Part B and is 65 or older, it is a one-time period, and it does not repeat every year like Medicare open enrollment. Outside it, a person may have to pay more for a policy, and unless a specific federal or state protection applies to their situation, the insurance company is allowed to deny a policy if the person does not meet its medical underwriting requirements. For a person who switches to Original Medicare in the fall, Medicare.gov notes that a separate drug plan may be needed and that there are limits on when Medigap can be added.
Medicare Advantage has a second window. A person already in a Medicare Advantage plan has a separate period from January 1 through March 31. Medicare.gov says it lets such a person switch to another Medicare Advantage plan or drop the plan and return to Original Medicare, and the regulation says the person may make an election once during the first 3 months of the year. The period is only for people already in a Medicare Advantage plan, so it does not move someone from Original Medicare into one.
| Window | Dates | Who it applies to | What it allows |
|---|---|---|---|
| Open enrollment | October 15 to December 7 | People with Medicare | Change Medicare Advantage or Part D coverage; move between Original Medicare and Medicare Advantage |
| Medicare Advantage open enrollment | January 1 to March 31 | People in a Medicare Advantage plan | One change: another Medicare Advantage plan, or Original Medicare |
| Part B Initial Enrollment Period | Seven months around the 65th birthday for most people | People first becoming eligible at 65 | First sign-up for Part B |
| Part B General Enrollment Period | January 1 to March 31 | People who did not sign up earlier | Sign up for Part B; a late enrollment penalty can apply |
| Medigap open enrollment | Six months from age 65 with Part B | People buying a Medigap policy | Buying a Medigap policy without medical underwriting; outside it, this generally needs a specific federal or state protection |
Where Income Enters: The Premium Comes From an Older Return
Open enrollment changes the plan. It does not change the income-related monthly adjustment amount, the extra premium higher-income members pay for Part B and Part D. Social Security generally uses information from two years prior to the premium year, so premiums for 2027 generally rest on the 2025 tax return.
For 2026, CMS sets the standard Part B premium at $202.90 a month. The extra amount applies above $109,000 of modified adjusted gross income for a single filer and above $218,000 for a joint return. These are the 2026 amounts, and CMS publishes each year’s amounts separately. Our August Insight explains the two-year lookback and how a qualifying life-changing event can change the year Social Security uses, and the August Resource sets out six decisions between ages 63 and 66.
Free Help Comparing Medicare Plans
Among the tools Medicare.gov lists are a local State Health Insurance Assistance Program (SHIP), which offers free personalized health insurance counseling, and a “Compare plans in your area” tool for Medicare Advantage, other Medicare health plans and Medicare drug plans.
Frequently Asked Questions
What are the Medicare open enrollment dates for 2026?
Open enrollment runs from October 15 to December 7, 2026, and changes take effect January 1, 2027. Medicare.gov says open enrollment happens from October 15 to December 7 each year, and changes made then take effect January 1 of the next year.
What happens if I do nothing during Medicare open enrollment?
Not necessarily anything. CMS says people who want to keep their current coverage generally do not need to re-enroll. Because plan costs and benefits can change from year to year, CMS encourages beneficiaries to review their current coverage and compare their options.
What is the standard Medicare Part B premium for 2026?
For 2026, CMS sets the standard Part B premium at $202.90 a month, and members above the income thresholds pay more. CMS publishes each year’s amounts separately, so check Medicare.gov for the 2027 figure.
Can I sign up for Part B during open enrollment?
Not through open enrollment itself. The fall window is for changing Medicare Advantage and Part D coverage. Part B sign-up runs through the Initial Enrollment Period, which for most people falls around the 65th birthday, a Special Enrollment Period for people who qualify, or the General Enrollment Period from January 1 to March 31, when a late enrollment penalty can apply.
Can I change my Medicare Advantage plan after December 7?
Outside a Special Enrollment Period, a person already in a Medicare Advantage plan can make one change between January 1 and March 31, either to another Medicare Advantage plan or back to Original Medicare.
From the August Medicare and Healthcare Series
INSIGHT — Why Medicare Planning Isn’t About Medicare — It’s About the Two-Year Lookback
RESOURCE — The Medicare Planning Audit: Six Decisions Between 63 and 66
CONVERSATION — Healthcare Planning Before Medicare: What Changed in the Affordable Care Act for 2026
MARKET COMMENTARY — What August’s Cooling Inflation and Negative Payroll Print Mean for Medicare Timing
Schedule with Security Financial Management
If you would like to connect with our team about how Medicare premiums and the two-year income lookback fit into your retirement income plan, schedule a conversation or call (407) 740-6553. Households work with a lead advisor who knows your plan, backed by specialists in investment, retirement, estate and insurance who coordinate every part of it. Choosing a Medicare plan itself is best done with a licensed health insurance professional or your local SHIP.
About the Author
Dave Allen, CFP® · Managing Partner, Security Financial Management · CRD #1210763. Verify credentials at BrokerCheck by FINRA.
Disclosures
This article is for informational and educational purposes only and does not constitute investment, tax, medical or legal advice. Medicare rules, premiums, thresholds and enrollment dates are as published by CMS, Medicare.gov and the Social Security Administration and change annually; confirm current details at Medicare.gov. Health insurance decisions should be made with a licensed health insurance professional, and tax consequences reviewed with a qualified tax professional. Security Financial Management is not affiliated with or endorsed by Medicare or any government agency. Past performance does not guarantee future results. Securities offered through Kestra Investment Services, LLC, member FINRA/SIPC (Kestra IS). Investment advisory services offered through Kestra Advisory Services, LLC (Kestra AS). Security Financial Management, Bluespring Wealth Partners, LLC, Kestra IS and Kestra AS are affiliated through common ownership by Kestra Holdings.