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Delaying Part B vs enrolling at 65
Written by My65 Playbook Editorial Team
Last reviewed
Part B carries a monthly premium, so the urge to delay it is rational — why pay for coverage you may not need yet? And delaying is genuinely safe for a large group of people. The trouble is that it is quietly expensive for everyone else, and the two groups feel identical from the inside. One question separates them: is the coverage you would rely on instead active employer coverage, or something that merely resembles it?
How to think about this
Run the test before the math. Delaying Part B is protected only when you are covered through active employment — yours or your spouse's — at an employer large enough that its plan pays before Medicare. That protection is the special enrollment period: it lets you add Part B later, penalty-free, when the employment ends. Everything else — COBRA, retiree plans, marketplace coverage, VA care on its own — fails the test: the delay is unprotected, the penalty clock runs, and the coverage may even pay poorly once you are Medicare-eligible. If you pass the test, delaying is a reasonable budget choice. If you fail it, the premium you are avoiding is smaller than the surcharge you are accruing.
At a glance
| What changes | Delaying Part B | Enrolling at 65 |
|---|---|---|
| When it is protected | Only with active employment coverage from a sufficiently large employer — yours or your spouse's. | Always — enrolling in your initial window needs no protection. |
| The penalty mechanics | Unprotected delay adds a permanent surcharge that grows with each full year missed. | No penalty exists to think about. |
| Coverage while you wait | Your employer plan carries you; other coverage types may pay as if Medicare were primary even though you never enrolled. | Medicare is in place, coordinating normally with anything else you hold. |
| When coverage can start later | With protection: a limited special window when employment ends. Without: you may wait for a general window, with a gap. | Not applicable — you are already in. |
| Effect on Medigap rights | Your one-time Medigap open enrollment is tied to Part B starting — delaying Part B delays that window too, which can be fine or costly depending on your plans. | Your Medigap guaranteed-issue window opens on schedule alongside Part B. |
Delaying Part B
- You or your spouse are actively employed with group coverage at a large-enough employer, verified — not assumed.
- That plan's drug coverage is confirmed creditable, in writing.
- You would genuinely use the premium savings and you have diarized when the protection ends.
Enrolling at 65
- Your coverage is COBRA, retiree, marketplace, VA-only, or nothing — the delay is unprotected.
- The employer is small enough that Medicare would pay first anyway.
- You cannot say with certainty which category your coverage falls into — uncertainty here defaults to enrolling.
Watch out for
- The penalty is permanent, not a fee you pay once. An unprotected delay adds a surcharge to every future Part B premium, growing with each full year missed — a decision made at 65 that bills you at 85. Its size is not the point; its permanence is.
- Look-alike coverage is the trap. COBRA, retiree plans, and marketplace coverage all feel like employer insurance and none of them protect a delay. The test is active employment, not the logo on the card.
- When the protection ends, the window is shorter than people think — and it runs from when employment or coverage ends, not from when you feel ready. Mark it before you need it.
- Delaying Part B also postpones your one-time Medigap guaranteed-issue window, which is tied to Part B's start. Usually that works out fine; if your health changes during the delay, it matters that the window waited for you.
Common questions
- Is delaying Part B ever simply the right call?
- Yes — with verified active employment coverage from a large employer, delaying is routine and safe, and many working people do it. The mistake is not delaying; it is delaying on the strength of coverage that does not qualify.
- Does Part A follow the same rules?
- Mostly no — Part A is premium-free for most people, so most take it at 65 regardless. The exception is HSA contributions, which must stop when Part A begins; if you fund an HSA, the Part A timing needs its own decision.
- How do I verify my employer coverage actually protects a delay?
- Two facts, in writing: the employer's size category, and whether the drug coverage is creditable. The benefits administrator can state both. Verbal reassurance is not evidence you can use if a penalty is later assessed.
- I already delayed without protection. What now?
- Enroll at the next available window rather than compounding the wait — the surcharge grows with each full year, so stopping the clock is the move. A licensed agent can map your fastest path back in.