Susan Park
You’re turning 65, still working, and your inbox is suddenly full of Medicare mailers that all seem to assume you’re about to retire. You might be wondering whether any of this actually applies to you right now, or whether you can just set it aside until you’re ready to stop working. That’s exactly the question I want to answer here, because getting this wrong can cost you real money and create coverage headaches that follow you for years.
Here’s what I tell people in this situation first: the rules depend almost entirely on the size of your employer.
The Number That Changes Everything: 20 Employees
| Employer Size | Medicare Primary/Secondary | Part A Enrollment | Part B Enrollment | Part D Enrollment |
|---|---|---|---|---|
| 20+ employees | Employer plan is primary | Enroll at 65 (generally recommended) | Can delay without penalty if creditable coverage exists | Can delay without penalty if creditable coverage exists |
| Fewer than 20 employees | Medicare is primary | Enroll at 65 | Enroll at 65 to avoid penalty | Enroll at 65 to avoid penalty |
Your employer’s size is the single most important fact you need to know before you make any Medicare decision at 65. If the company you work for has 20 or more employees, your employer-sponsored health plan is considered the “primary” payer, meaning it pays first on your claims, and Medicare would only pay second. In that situation, you generally have real options, and delaying Medicare enrollment is often perfectly fine.
If your employer has fewer than 20 employees, Medicare becomes the primary payer the moment you’re eligible, even if you haven’t enrolled. That means your employer plan may start paying as if Medicare had already covered its share, leaving you responsible for a chunk of your bills that Medicare would have covered if you’d actually enrolled. This catches people off guard constantly, and it’s one of the most expensive mistakes I’ve seen.
So before you do anything else, ask your HR department two questions: how many employees does this company have, and does the plan pay primary or secondary to Medicare? Get the answer in writing if you can.
What “Delaying Medicare” Actually Means (And Doesn’t Mean)
Helpful resource: OMRON Platinum Blood Pressure Monitor Upper Arm is a top-rated option for this. (As an Amazon Associate this site earns from qualifying purchases.)
Assuming you work for a company with 20 or more employees, you can delay Medicare enrollment past 65 without penalty, but only certain parts of it.
Medicare Part A, which covers hospital stays, is almost always free if you’ve worked and paid Medicare taxes for at least 10 years (40 quarters). Most people in this situation should go ahead and enroll in Part A at 65 even if they’re keeping their employer coverage. There’s almost no reason not to, since it costs nothing and can act as a secondary layer of coverage for hospitalizations.
Part B is a different story. Part B covers outpatient care and doctor visits, and it has a monthly premium (currently around $185, though this changes each year and your income can affect it). If your employer coverage is solid, paying that premium for coverage you don’t really need makes no sense. You have the right to delay Part B, and if you qualify under the active employment exception, you will not face a late enrollment penalty for doing so.
Part D, which covers prescription drugs, is where people get confused. The penalty rule for Part D is separate from Part B. If you have creditable drug coverage through your employer (your HR department can tell you if this applies), you can delay Part D enrollment without penalty too. If you’re not sure whether your coverage is “creditable,” ask your employer plan administrator directly. They’re required to notify you each year whether it qualifies.
What I’d push back on here: a lot of people assume they can figure this out later. They can’t, not without risk. You have a Special Enrollment Period (SEP) that lasts for 8 months after your employment ends or your employer coverage ends, whichever comes first. Miss that window, and you’ll pay a Part B late enrollment penalty of 10% for every 12-month period you were eligible but didn’t enroll. That penalty is permanent. It follows you for the rest of your life.
If You Have an HSA, Pay Attention to This
Medicare Initial Enrollment Period - Sign Up for Medicare at Age 65 · Medicare on Video - Medicare Specialist on YouTube
Here’s something I wish more people knew before they turned 65. If you’re currently contributing to an HSA (Health Savings Account) through a High Deductible Health Plan, enrolling in any part of Medicare, including Part A, makes you ineligible to keep contributing.
The moment your Medicare coverage begins, your HSA contributions stop. This matters because if you enroll in Part A at 65, Medicare can retroactively cover the six months before your enrollment date (or back to your 65th birthday, whichever is shorter). That retroactive coverage can create excess HSA contributions if you were contributing during that period, and the IRS will not be amused.
What I tell people in this specific situation: if you’re still working at 65, still contributing to an HSA, and want to keep doing so, you may want to delay both Part A and Part B. That’s a legitimate choice if your employer plan is your primary coverage and your employer has 20 or more employees. But stop contributing to the HSA at least six months before you plan to enroll in Medicare, so you don’t get caught by the lookback rule. Your benefits administrator and a tax advisor should both be in the loop on this one.
The Enrollment Windows You Actually Need to Know
Your Initial Enrollment Period (IEP) for Medicare is a 7-month window: the three months before your 65th birthday month, your birthday month itself, and three months after. Most mailers and articles focus heavily on this window, which is fine if you’re actually retiring at 65.
If you’re not retiring, the IEP still opens, but you may have good reason not to act on it. You’ll use your Special Enrollment Period instead, which is triggered by your loss of employer coverage when you eventually do retire or leave your job. That 8-month SEP is what protects you from penalties.
One thing people don’t always realize: the SEP starts the day your employment or your coverage ends, not the day you apply for Social Security or turn in your resignation letter. The clock starts immediately. I’d recommend not waiting until the last minute. Aim to enroll in Part B within the first couple months of that SEP, because there can be processing delays that affect when your coverage actually starts.
AARP’s Medicare resource center has a useful breakdown of these timelines if you want to double-check the sequence, and your local State Health Insurance Assistance Program (SHIP) offers free, unbiased counseling, which I’d honestly recommend for anyone in this situation. SHIP counselors have no products to sell you. That matters.
What About Spouses and Dependents on Your Employer Plan?
If your spouse or dependents are on your employer health plan, your retirement affects them too, and Medicare only covers you. Spouses don’t automatically get Medicare coverage through your enrollment. They’ll need their own coverage when your employer plan ends.
If your spouse is under 65, they’ll typically turn to COBRA (which extends your employer plan temporarily, though it’s expensive) or a marketplace plan through Healthcare.gov. If your spouse is already 65 or older but hasn’t enrolled in their own Medicare, they’ll want to do that before your coverage ends. This is a detail that families often miss in the rush of retirement planning, and it can create a stressful gap.
Plan this piece at least a few months ahead. Don’t treat it as an afterthought.
Getting this right is genuinely worth the time it takes. The rules aren’t simple, but they’re learnable, and the stakes are real enough that you don’t want to guess. If you’re uncertain about your specific situation, a SHIP counselor is one of the best resources available to you, completely free of charge. You don’t have to sort this out alone.
This article is for informational purposes only. Medicare rules change annually. Always verify current plan details at Medicare.gov or by calling 1-800-MEDICARE (1-800-633-4227). This site does not sell insurance or recommend specific plans.
Sources
- OMRON Platinum Blood Pressure Monitor Upper Arm
- State Health Insurance Assistance Program (SHIP)
- Withings Body+ Smart Scale with BMI and Body Composition
- Copper Compression Knee Support Sleeve
- RDNE Stock project
Disclosure: As an Amazon Associate, we earn a small commission from qualifying purchases at no extra cost to you. We only recommend products that genuinely support the topics covered in this article.
- Medicare For Dummies (~$22), The definitive consumer guide to Medicare, enrollment windows, Part A/B/C/D, and supplement plans.
- Get What’s Yours for Medicare (~$17), Maximize your Medicare benefits and minimize out-of-pocket costs. Covers Part D drug coverage gaps and Medigap in depth.
Recommended Resources
Disclosure: As an Amazon Associate, we earn a small commission from qualifying purchases at no extra cost to you. We only recommend products that genuinely support the topics covered in this article.
- Medicare For Dummies (~$22), The definitive consumer guide to Medicare, enrollment windows, Part A/B/C/D, and supplement plans.
- Get What’s Yours for Medicare (~$17), Maximize your Medicare benefits and minimize out-of-pocket costs. Covers Part D drug coverage gaps and Medigap in depth.
