More people are working past 65 than ever — and almost all of them hit the same wall of confusion: do I have to take Medicare, or can I keep the plan I already have at work? The honest answer is "it depends," but not on a hundred things. It mostly comes down to one factor: the size of your employer. Get that piece right and the rest falls into place. Let's walk through it the SRIG way — the complex made simple.
The One Number That Decides Everything: 20
When you have both Medicare and an active employer plan, one pays first (the "primary payer") and the other pays second. Which is which depends almost entirely on how many employees your company has.
Large Employer
Your group plan is primary and Medicare is secondary. Because your job coverage is already handling the bulk of your care, many people in this situation choose to delay Part B while still working — and can generally do so without a penalty.
Small Employer
Medicare becomes primary and your group plan is secondary. In this case you'll generally want to enroll in both Part A and Part B at 65 — if you don't, your employer plan may pay as if Medicare already paid, leaving you with surprise bills.
Part A Is Usually Free — So Most People Take It
Whatever your employer size, most people qualify for premium-free Part A (hospital coverage) at 65 based on their work history. Since it generally costs nothing, many take it as a bit of extra secondary hospital coverage while they keep working.
The HSA Trap
This one catches people off guard every year. The IRS does not allow you to keep contributing to a Health Savings Account once you're enrolled in any part of Medicare — including premium-free Part A. If you want to keep funding your HSA while you work, you may need to delay Medicare entirely, including Part A.
Don't Forget Your Prescription Coverage
Your employer's drug coverage matters too. If your workplace plan is considered "creditable" — meaning it's expected to pay, on average, at least as much as standard Medicare drug coverage — you can generally delay a Part D plan without a penalty. Most large employer plans meet this bar, but not all.
- Ask for it in writing. Request your plan's annual "Notice of Creditable Coverage" and keep it — you may need it later to prove you had qualifying drug coverage.
- If it's not creditable, you'll generally want a Part D plan when first eligible to avoid a lasting late-enrollment penalty.
When You Retire: The 8-Month Clock
Here's the deadline that carries a lifelong penalty if you miss it. Once your employment or your employer coverage ends — whichever comes first — you get a Special Enrollment Period of 8 months to sign up for Part B without a late penalty.
So… Should You Take Medicare or Keep Employer Coverage?
Even when you're allowed to delay, that doesn't always mean you should. Sometimes Medicare plus a supplement is actually cheaper and better than what you're paying at work. It comes down to running the numbers on your specific situation:
- Your share of the employer premium vs. the Part B premium (which is $202.90 for most people in 2026) plus a supplement or Advantage plan.
- Deductibles and out-of-pocket costs on each side.
- Your doctors and prescriptions — and whether they're covered under each option.
- Whether you're protecting an HSA or have a younger spouse or dependents on your plan.
Common Questions
Do I have to sign up for Medicare if I have employer coverage?
Can I keep contributing to my HSA on Medicare?
Does COBRA let me delay Part B?
What is the 8-month Special Enrollment Period?
Should I keep my employer plan or switch to Medicare?
Your Next Step
Working past 65 gives you options — but only if you handle the timing right. Here's how to stay protected:
- Watch the video above for the plain-English walkthrough.
- Confirm your employer's size and payer status in writing with HR.
- Book a Blueprint consultation — we'll compare your options and time your transition, free.
Your blueprint is waiting. Let's build it together.