Turning 65 While Still Working: What You Actually Need to Do

Turning 65 while still employed raises a question that trips up a lot of people: do you need to sign up for Medicare now, or can it wait until you actually retire? The answer depends mainly on the size of your employer.

The 20-Employee Rule

If your employer has 20 or more employees, your group health plan is generally considered primary, and you can usually delay Medicare Part B without a late penalty until you actually stop working or lose that coverage. If your employer has fewer than 20 employees, Medicare typically becomes primary at 65 regardless of your employment status, and delaying Part B can leave real gaps in what gets paid.

Part A Is Usually Worth Taking Either Way

Because Part A is premium-free for most people, there is rarely a downside to enrolling in it at 65 even while still working — with one notable exception: if you or your spouse are actively contributing to a Health Savings Account (HSA), enrolling in any part of Medicare stops new HSA contributions. If that applies to you, it is worth a specific conversation before enrolling.

What Happens When You Actually Retire

Once your employment or employer coverage ends, you get an 8-month Special Enrollment Period to sign up for Part B without penalty. Missing that window means potentially waiting for the general enrollment period and facing a late enrollment penalty — so this date matters and is worth marking clearly.

Questions Worth Asking Your HR Department

• Is our group health plan considered primary or secondary to Medicare at my age?
• How many employees does our company have for Medicare coordination purposes?
• What documentation will I need from HR when I do enroll in Medicare later?

Getting this timing right protects you from penalties and coverage gaps — and it is a genuinely common enough situation that there is no reason to guess instead of asking.