Glossary
Late Enrollment Penalty (Part B)
A 10% permanent surcharge on your Part B premium for every full 12-month period you delayed enrollment without qualifying coverage.
Also known as: LEP, Part B penalty
What is it?
If you don't sign up for Part B when you're first eligible and don't have qualifying employer coverage, you pay a 10% penalty for every full 12-month period you went without it — for as long as you have Medicare.
Why does it matter?
The penalty is permanent and compounds across years. A retiree who delayed 4 years pays 40% more for Part B forever. Worse: they had no TFL during those 4 years.
When you'll encounter it
Assessed when you finally enroll in Part B during a GEP.
Impact on Medicare
Increases your monthly Part B premium for life.
Impact on TRICARE For Life
If you delayed Part B, you had no TFL during that period. Once you enroll, TFL resumes — but the penalty doesn't go away.
Common misconceptions
- "The penalty falls off after a few years." — It's permanent. There is no expiration.
Related lessons
Related glossary terms
Official sources
Last reviewed January 2026 against the 2026 Medicare & You and TRICARE For Life handbooks.