Part B Late-Enrollment Penalty
Understand when the penalty may apply and how qualifying active-employment coverage affects timing.
When the Part B penalty can arise
If you miss your initial Part B sign-up window and do not qualify for a Special Enrollment Period, the premium can increase by 10% for every full 12-month period you could have had Part B but did not. The penalty generally lasts as long as you have Part B.
Official source: Medicare: Avoid penalties ↗
The 2026 calculation example
Medicare gives a two-full-year delay example: 20% of the standard $202.90 Part B premium in 2026, subject to Medicare’s billing rules. An income-related monthly adjustment is a different charge. Your applicable premium can differ.
Official source: Medicare: Avoid penalties ↗ · Medicare: 2026 costs ↗
Employment exception has conditions
People covered under eligible current-employment group health insurance can have a Part B Special Enrollment Period, generally while that coverage remains and for eight months afterward. COBRA and retiree coverage are different; ask the employer and verify the dates before delaying.
Official source: Medicare: When to sign up ↗ · Medicare: COBRA coverage ↗
How to act
Use SSA’s Medicare application route and Medicare’s enrollment form guidance. Keep dated proof of employment coverage and obtain an official eligibility determination if timing is disputed.
Official source: SSA: Sign up for Part B only ↗ · Medicare: Enrollment forms ↗