Approaching your 65th birthday brings up a lot of questions about retirement benefits and healthcare coverage. In this first installment of our “I’m Turning 65, Now What?” series, we explain navigating Medicare enrollment if you work for a small business with fewer than 20 employees. 

Medicare follows specific rules for small company employees. At age 65, Medicare becomes your primary insurance if your employer has fewer than 20 employees — no exceptions. Your current health plan transitions to secondary coverage, paying only after Medicare has covered its share.

Many soon-to-be Medicare enrollees overlook this critical detail, which can result in coverage gaps or unexpected bills. The size of your company fundamentally changes how Medicare works with your existing benefits. Getting it right means understanding exactly when to enroll, how your coverage coordinates, and what steps to take to protect your access to healthcare.

This guide breaks down the essentials of Medicare enrollment for small business employees, providing clear action steps to maintain solid coverage and control costs.

Why company size matters for your Medicare coverage

Small companies play by different Medicare rules. The moment you turn 65, Medicare steps up as your main health insurance, with your company’s plan taking a supporting role. 

Most people don’t realize this shift is mandatory. Skip Medicare enrollment, and you’ll face some tough consequences: gaps in coverage, denied claims, and out-of-pocket costs that could have been avoided. Your company’s insurance won’t pick up Medicare’s share, no matter how good your workplace coverage might be.

Your doctor’s office sends bills to Medicare first. After Medicare pays its portion, your workplace plan reviews what’s left. But this only works if you’ve enrolled in both Medicare Part A and Part B during your Initial Enrollment Period. The good news? You’re entitled to both, and setting them up properly means seamless coverage from day one.

Small business employees: Your Medicare deadline matters

Working past 65 brings unique Medicare requirements when you’re with a small employer. Your Initial Enrollment Period opens three months before your 65th birthday month. Missing this window can cost you lifelong late enrollment penalties and months without proper coverage.

Part A enrollment typically comes with no premium if you’ve worked for at least 10 years. Part B requires a monthly premium, but delaying enrollment when you work for a small company leads to permanent penalties. These penalties grow every month you wait, adding 10% to your premium for each 12-month period you could have had Part B but didn’t.

Some employers offer to keep you on their insurance without Medicare. While generous, this approach can backfire. Medicare pays first for small company employees over 65. If you stay only on your employer’s plan, they might deny claims that Medicare should have covered. This leaves you responsible for costs that proper enrollment would have prevented.

How Medicare works with small business health plans

Medicare takes control of your healthcare coverage at 65 when you work for a small business. This means every medical visit follows a specific payment order: Medicare reviews and pays its share first, then your workplace plan picks up approved leftover costs.

Most medical services fall under this two-step process. Your doctor sends claims to Medicare, which typically covers 80% of approved charges. Your employer’s plan then steps in as secondary coverage, potentially handling some or all of the remaining 20%. This teamwork between plans helps minimize your out-of-pocket costs.

Keep your Medicare card handy — you’ll need to show it at every appointment. Your employer’s insurance card becomes your backup, not your main coverage. Smart move: Let your doctors know you have both types of coverage to prevent billing headaches and ensure proper claim processing.

Medicare enrollment: Your step-by-step guide

Ready to tackle Medicare enrollment while keeping your small company job? We’ve mapped it out for you. Getting started three months before your 65th birthday puts you in the driver’s seat for a smooth transition. Here’s what you need to do:

1. Start Medicare enrollment three months before turning 65
   •  Seek guidance from a licensed insurance agent (like ours at SmartMatch)
   • Get help navigating your enrollment options
   • Ensure proper documentation of your enrollment date
2. Meet with your benefits administrator
   • Confirm how workplace coverage coordinates with Medicare
   • Review prescription drug coverage needs
   • Understand which plan pays first for specific services
3. Track important dates
   • Initial Enrollment Period: 3 months before your birth month
   • Runs through your birth month and ends 3 months after
   • Special Enrollment Periods: Available for qualifying life events like moving or losing coverage

• Annual Enrollment Period: October 15 through December 7

4. Gather necessary documents
   • Social Security card
   • Birth certificate
   • Proof of citizenship
   • Current health insurance information

Your small company coverage needs Medicare as its partner at 65.. Getting everything lined up early means your coverage stays solid and your wallet stays happy.