MEDICARE BASICS

Missing your enrollment window can cost you more every month — for life. Here’s what you need to know to enroll on time.

April 8, 2026  ·  5 min read  ·  Medicare Enrollment

Medicare Part B covers 80% of most outpatient care and 100% of many preventive services — but signing up at the wrong time can permanently raise your monthly premium. The good news: with a little planning, the late enrollment penalty is entirely avoidable.

What is the Part B late penalty?

If you don’t enroll in Medicare Part B when you’re first eligible and don’t have a valid reason to delay, Medicare can charge you a late enrollment penalty. This penalty adds 10% to your monthly premium for every 12-month period you went without coverage — and it lasts for as long as you have Part B.

Key rule: You generally have an 8-month window to sign up for Part B after your employer or group health coverage ends. Miss that window without qualifying coverage, and the penalty applies.

When do you need to enroll?

The answer depends on your situation. Some people are enrolled automatically; others have flexibility to delay. Here’s a breakdown of the most common scenarios:

AUTO-ENROLLED You receive Social Security or Railroad Retirement benefits You’ll be enrolled in Medicare Parts A and B automatically at 65. If you have other creditable coverage, you can delay Part B — but you must decline it before your start date and enroll within 8 months of that coverage ending.

 

MAY DELAY You have employer coverage through a current job You can delay Part B if your employer has 20+ employees and provides creditable coverage. When that coverage ends, you qualify for a Special Enrollment Period — giving you 8 months to sign up penalty-free.

 

ENROLL CAREFULLY You have COBRA coverage COBRA does not count as creditable coverage for Medicare purposes. If you become eligible for Medicare first, you’ll generally need to enroll in Part B at 65. Delaying under COBRA can trigger the late penalty.

 

VA BENEFITS DON’T COUNT You have VA health care benefits VA benefits cover care only at VA facilities — they don’t qualify as creditable coverage for Medicare. It’s generally advisable to enroll in Part B when you become eligible to avoid penalty risk.

 

AUTO-ENROLLED You receive Social Security disability benefits You’ll be automatically enrolled in Medicare after 24 months of receiving disability benefits. You may delay Part B if you have other creditable coverage, but must act within 8 months of that coverage ending.

 

CHECK PLAN RULES You have retiree health coverage Whether you need Part B at 65 depends on your specific retiree plan. All retiree plan members must enroll in Part A. Talk to your plan administrator to understand how Medicare coordinates with your retiree benefits.

The bottom line

The Medicare Part B late penalty is one of the most avoidable costs in retirement healthcare — but only if you know the rules before your deadline arrives. The key is understanding whether your current coverage qualifies as ‘creditable’ and when your enrollment window opens and closes.

When in doubt, reach out to me, a licensed Medicare Insurance Advisor, before making any decisions about delaying enrollment. Have questions about your specific enrollment situation? Contact me to schedule a meeting for personalized guidance.

We don’t offer every plan available in your area. Any information provided is limited to those plans we do offer. Please contact Medicare.gov, 1-800-MEDICARE, or your State Health Insurance Program to get information on all of your options.