Quick answers
- When is Medicare open enrollment for 2027?
- October 15 to December 7, 2026. Coverage you choose starts January 1, 2027.
- What if my plan is ending in 2027?
- You can choose new coverage until February 28, 2027. Choose by December 31 so there's no gap, and check whether you can buy Medigap without health questions.
- Can I change plans after December 7?
- If you're in a Medicare Advantage plan, you can make one change from January 1 to March 31, 2027. Other changes need a special enrollment period.
- Is Medigap part of open enrollment?
- No. Medigap has its own rules. In Oklahoma, current Medigap policyholders can switch during the 60 days starting on their birthday.
- Does HealthChoice have the same dates?
- EGID's Option Period for Medicare-eligible members is also October 15 to December 7, and forms must be postmarked by December 7.
When is Medicare open enrollment for 2027?
The Annual Enrollment Period (AEP), often called open enrollment, runs October 15 to December 7, 2026. Changes take effect January 1, 2027. The dates are the same in every state. You can make more than one change; the last one you make by December 7 counts.
| Date | What happens |
|---|---|
| By September 30, 2026 | Your plan mails its Annual Notice of Change for 2027. |
| October 15, 2026 | Open enrollment opens. |
| December 7, 2026 | Open enrollment closes. HealthChoice Option Period forms must be postmarked by this date. |
| December 31, 2026 | Last day to choose a replacement for a plan that's ending without a gap in coverage. |
| January 1, 2027 | New coverage starts. The Medicare Advantage Open Enrollment Period opens. |
| February 28, 2027 | Special enrollment period ends for people whose plan didn't renew. |
| March 31, 2027 | The Medicare Advantage Open Enrollment Period ends. |
What can I change during open enrollment?
- Switch from Original Medicare to a Medicare Advantage plan.
- Switch from a Medicare Advantage plan back to Original Medicare.
- Change from one Medicare Advantage plan to another.
- Join, switch or drop a Part D drug plan.
To join a Medicare Advantage plan you must have Part A and Part B and live in the plan's service area. In Oklahoma, plans are approved county by county. See Medicare Advantage in Oklahoma and Part D in Oklahoma.
What changes in Part D for 2027?
- The yearly cap on what you pay out of pocket for covered Part D drugs is $2,400 in 2027. After you reach it, you pay nothing more for covered drugs that year.
- A Part D plan's deductible can be no more than $700 in 2027.
- Covered insulin costs no more than $35 for a month's supply.
- You can still spread drug costs over the year in monthly payments through the Medicare Prescription Payment Plan; ask your plan.
Plans also change their drug lists, pharmacy networks and premiums each year, which is why the Annual Notice of Change matters. See Medicare costs in 2027.
What should I check in my Annual Notice of Change?
- Find the notice. Your Medicare Advantage or Part D plan mails it by September 30. It lists what changes on January 1.
- Check your drugs. Make sure each prescription is still on the plan's drug list for 2027, and look at its tier and any new prior authorization or quantity limits.
- Check your doctors and hospitals. Confirm they are in the plan's 2027 network, including any hospital in Oklahoma City, Tulsa or another state you would use.
- Check your pharmacy. Make sure it's still in network, and whether it's a preferred pharmacy.
- Compare costs. Look at the premium, deductible, copays and the plan's out-of-pocket limit for 2027.
- Look for a non-renewal letter. If the plan is ending or leaving your county, you get a separate notice. Keep it; you'll need it to buy Medigap with guaranteed-issue rights.
What if my Medicare Advantage plan is ending in 2027?
If you do nothing, you go back to Original Medicare on January 1, without drug coverage. For 2027, some Medicare Advantage plans aren't renewing in parts of Oklahoma, and seven counties (Beaver, Cimarron, Ellis, Harmon, Harper, Roger Mills and Texas) have no Medicare Advantage plan open to everyone.
- Choose by December 7 during open enrollment, or by December 31 using the non-renewal special enrollment period, so your new coverage starts January 1.
- You have until February 28, 2027 to choose a Medicare Advantage or Part D plan, but coverage starts the first of the month after you choose.
- Medigap without health questions: because your plan is ending, you can buy Medigap Plan A, B, D, G, K or L (or C or F if eligible for Medicare before 2020) from any company, applying up to 63 days after your coverage ends (OAC 365:10-5-129.1).
See Oklahoma plans ending in 2027 to look up your county.
How many plans does Oklahoma have for 2027?
CMS's 2027 Landscape file lists 50 Medicare Advantage plans open to everyone in Oklahoma from 9 companies, 27 special needs plans and 9 standalone Part D plans. You can only choose plans sold in your county: Oklahoma County has 35 plans open to everyone, Tulsa County 32, Comanche County 19 and Woodward County 4. Find yours on our counties page.
After December 7: the Medicare Advantage Open Enrollment Period
From January 1 to March 31, 2027, if you're in a Medicare Advantage plan, you can make one change: switch to another Medicare Advantage plan, or drop your plan and return to Original Medicare and join a Part D plan. The change starts the first of the following month. This period isn't for people in Original Medicare who want to join a Medicare Advantage plan or switch Part D plans.
Special enrollment periods that run alongside open enrollment
- Moving to a new county or state. See moving to Oklahoma with Medicare.
- Getting or losing SoonerCare, a Medicare Savings Program or Extra Help. See SoonerCare and Medicare.
- Losing employer or retiree coverage.
- A federally declared disaster, such as tornadoes or ice storms, that kept you from making a choice. See tornadoes, ice storms and Medicare.
All dates are on Medicare enrollment periods.
Medigap isn't part of open enrollment
Open enrollment doesn't let you buy or change Medigap without health questions. In Oklahoma, two other rules do. Your one-time Medigap open enrollment period lasts 6 months from when you're 65 and have Part B. After that, Oklahoma's birthday rule lets current Medigap policyholders switch to a policy with the same or fewer benefits, from any company and without health questions, during the 60 days that start on their birthday each year (OAC 365:10-5-129(f)). The birthday rule doesn't help someone in Medicare Advantage move to Medigap. See Medigap in Oklahoma.
HealthChoice members: EGID's Option Period
If you get Medicare coverage through the Employees Group Insurance Division (EGID) as a state, education or local government retiree, EGID's 2027 guide says its Option Period runs October 15 to December 7, and forms must be postmarked by December 7. If you don't want changes, don't return the form; your coverage continues January 1. If your current EGID plan is being discontinued for 2027, it won't renew automatically and you must choose a new one. Enrolling in another plan with Part D benefits ends your Part D coverage through EGID. Call EGID Member Services at 405-717-8780 or 800-752-9475. See state and teacher retirees and Medicare.
How should I compare plans?
Start with your drugs, doctors and pharmacy, then compare costs for a typical year and a hard one. Medicare's Plan Finder at Medicare.gov lists plans in your ZIP code. To compare plans from the companies they work with, you can request a call from a licensed insurance agent, at no cost to you, or see plans for your ZIP code. You can also meet licensed insurance agents in Oklahoma.
Avoiding scams during open enrollment
- Medicare won't call you to sell a plan or ask for your Medicare number.
- Agents and plans can't call you, text you or come to your door without your permission.
- Don't give your Medicare number to anyone who contacts you out of the blue.
- Report suspected fraud to 1-800-MEDICARE (1-800-633-4227) or the Oklahoma Senior Medicare Patrol. Complaints about an insurance agent go to the Oklahoma Insurance Department at 1-800-522-0071.
Your open enrollment checklist
- Read your Annual Notice of Change. Note any change to drugs, network, costs, or a non-renewal.
- List your prescriptions, doctors and pharmacy. Bring the list when you compare plans.
- Compare plans sold in your county. Use Plan Finder or talk with a licensed insurance agent.
- Decide by December 7, 2026. If your plan is ending, decide by December 31 to avoid a gap.
- Watch for your new plan's welcome letter and ID card. Keep your old card until January 1.
Sources
- Medicare.gov — Joining a health or drug plan (Open Enrollment and Medicare Advantage Open Enrollment)
- Medicare.gov — Your yearly Medicare review (Annual Notice of Change)
- Medicare.gov — Special Enrollment Periods (plan non-renewal, moving, Medicaid, disasters)
- CMS — CY 2027 Rate Announcement (Part D out-of-pocket threshold and deductible)
- CMS — Medicare Advantage and Part D Landscape files, contract year 2027 (plan counts)
- eCFR — 42 CFR 422.62, election of coverage under an MA plan
- eCFR — 42 CFR 422.2264, contact with beneficiaries (unsolicited contact)
- Okla. Admin. Code § 365:10-5-129.1, Guaranteed issue for eligible persons (via Cornell LII)
- Oklahoma Insurance Department — New Medicare Supplement Open Enrollment FAQs (birthday rule)
- Employees Group Insurance Division (EGID, Oklahoma Health Care Authority) — 2027 Medicare Options Benefit Guide (Option Period)
Every question in this guide
- Can I go back to Original Medicare from Medicare Advantage?
- Can I switch Medicare Advantage plans after open enrollment ends?
- My Medicare Advantage plan is ending in 2027 in Oklahoma. What do I do?
- When is Medicare open enrollment in Oklahoma for 2027?
- Which Medicare companies are leaving Oklahoma in 2027?
Frequently asked questions
When is Medicare open enrollment in Oklahoma for 2027?
The Annual Enrollment Period runs October 15 to December 7, 2026, the same dates nationwide. Any change you make takes effect January 1, 2027. If you change your mind, the last change you make by December 7 is the one that counts.
What can I change during open enrollment?
You can switch from Original Medicare to a Medicare Advantage plan, switch from Medicare Advantage back to Original Medicare, change Medicare Advantage plans, or join, switch or drop a Part D drug plan. Open enrollment doesn't include Medigap policies, which follow their own rules.
My Oklahoma Medicare Advantage plan is ending in 2027. What should I do?
Choose a new Medicare Advantage plan, or Original Medicare with a Part D plan, by December 7 or by December 31 at the latest so your new coverage starts January 1. A special enrollment period lets you choose until February 28, 2027, but waiting past December means a gap. Because your plan is ending, you may also be able to buy certain Medigap policies without health questions until 63 days after your coverage ends.
Can I switch Medigap policies during open enrollment in Oklahoma?
Open enrollment doesn't give Medigap rights. Oklahoma's birthday rule does: if you already have Medigap, you can switch to a policy with the same or fewer benefits, from any company, without health questions, during the 60 days that start on your birthday each year (OAC 365:10-5-129(f)).
I'm a state or education retiree with HealthChoice. Do I use Medicare's open enrollment?
EGID runs its own Option Period for Medicare-eligible members on the same dates, October 15 to December 7, with forms postmarked by December 7. If you don't want changes, EGID says not to return the form and your coverage continues. Joining an outside plan with Part D can end your EGID Part D coverage, so call EGID at 405-717-8780 or 800-752-9475 first.
Medicare in your Oklahoma county
Plans, local agents and help, county by county: Oklahoma · Tulsa · Cleveland · Canadian · Comanche · Rogers · Wagoner · Payne · Pottawatomie · Creek · Muskogee · Garfield · Grady · Washington · Logan · Bryan · Le Flore · Carter · Cherokee · McClain · All 77 counties →
