The 20-employee rule
| Your coverage at 65 | Who pays first | Need Part B now? |
|---|---|---|
| Your or your spouse's current job, employer with 20 or more employees | Job-based plan | No, you can usually delay |
| Your or your spouse's current job, employer with fewer than 20 employees | Medicare | Usually yes |
| COBRA, retiree coverage or a Marketplace plan | Medicare | Yes |
Ask your employer's benefits office, in writing, whether its plan pays first for workers 65 and older and whether it expects you to enroll in Medicare. A small employer's plan may pay only after Medicare, leaving large bills if you don't have Part B.
Signing up later without a penalty
- Plan ahead. Apply a month or two before your job coverage ends so Part B starts the day after.
- Get form CMS-L564 from your employer. It shows the dates of your group coverage from current work.
- Submit form CMS-40B with it. Online, by fax or mail, or at an Ohio Social Security office.
- Choose your other coverage. You have 2 full months after job coverage ends to join a Medicare Advantage or Part D plan. Your Ohio Medigap open enrollment starts with your Part B and lasts 6 months; Ohio has no birthday rule, so don't let it pass.
If you miss the 8-month window, you'll wait for the General Enrollment Period (January 1 to March 31) and may pay 10% more for Part B for each full 12 months without it, usually for life. Keep your employer's annual creditable drug coverage notices, too, to avoid a Part D penalty.
Ohio public employees and rehired retirees
If you're a working Ohio public employee, your active plan follows the same rule. If you've retired and gone back to work, your retirement system's rules matter: OPERS says that if you don't enroll in Medicare because of active employment, you won't get its HRA deposits. See Ohio public retirement systems and Medicare and working past 65. To review options when you retire, you can request a call from a licensed insurance agent.
Related questions
What if I miss my enrollment period?
Penalties and your next chance.
How do I sign up for Medicare in Ohio?
Online, by phone or in person.
When should I sign up if I'm turning 65?
Your 7-month window.
Sources
- Medicare.gov — Working past 65
- Medicare.gov — Which insurance pays first?
- Medicare.gov — Avoid late enrollment penalties
- Social Security — Apply for Part B during a special enrollment period
- OPERS — 2026 Health Care Program Guide
More questions in this guide
- Can I get Medicare before 65 in Ohio?
- How do I sign up for Medicare in Ohio?
- What are the Medicare deadlines in Ohio for 2027?
- What happens if I miss my Medicare enrollment period in Ohio?
- What happens to my Medicare if I move to Ohio?
- When should I sign up for Medicare if I'm turning 65 in Ohio?
Part of the guide: Medicare enrollment periods in Ohio · All questions
Frequently asked questions
Should I take Part A while I'm still working?
If it's premium-free, many people do, because it can help as secondary hospital coverage. But if you contribute to a health savings account, Medicare.gov says you and your employer should stop contributions 6 months before you apply for Medicare or Social Security, since Part A can be backdated up to 6 months.
What forms do I need to sign up for Part B later?
Form CMS-40B, the Part B application, and form CMS-L564, which your employer completes to show your group coverage from current work. You can submit them online at ssa.gov, by fax or mail, or at a Social Security office.
I teach in an Ohio school district and plan to keep working. Do I need Part B now?
Your active-employee health plan is coverage from current work, so the 20-employee rule applies; ask your district's benefits office whether its plan pays first for people 65 and older. STRS Ohio's Part B requirement applies once you're in its retiree medical plan.
Medicare in your Ohio county
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