Medicare Late Enrollment Penalties (2026): Part A, B & D Explained

Estimate your penalty

Use the calculator below for a quick estimate, then read on for how each penalty works.

Missing a Medicare enrollment window can cost you for years — sometimes for life. This guide explains the 2026 late enrollment penalties (LEP) for Part A, Part B, and Part D, shows exactly how each is calculated, and includes a quick reference table so you can estimate your own. Penalty amounts are estimates; your actual penalty is determined by Medicare and the Social Security Administration.

The three penalties at a glance

For Part B and Part D, an unexcused delay means a permanent monthly increase. The Part A penalty is temporary and only applies to people who pay a premium for Part A in the first place — most people get Part A free.

Part A late enrollment penalty

Most people pay $0 for Part A because they (or a spouse) worked and paid Medicare taxes for at least 40 quarters (10 years). If that's you, there is no Part A penalty. A penalty only applies if you have to buy Part A and signed up late.

The 2026 Part A premiums are:

• $0/month — 40 or more quarters of Medicare taxes
• $311/month — 30 to 39 quarters
• $565/month — fewer than 30 quarters

How it's calculated: Your premium goes up 10%, and you pay that surcharge for twice the number of years you could have had Part A but didn't sign up. The penalty does not grow the longer you wait — it's a flat 10%.

Example: If you pay the $565 premium and delayed 2 years, your penalty is 10% × $565 = $56.50/month, paid for 4 years (2 × 2). That's about $2,712 in total penalties.

Part A penalty reference (10% surcharge)

Part B late enrollment penalty

If you don't sign up for Part B when first eligible (and don't have other qualifying coverage), you may pay a penalty for as long as you have Part B. The penalty is a 10% increase for each full 12-month period you could have had Part B but didn't.

The standard Part B premium for 2026 is $202.90/month (higher if you pay an income-related adjustment, IRMAA).

How it's calculated: 10% × the number of full years late × the standard premium. Only complete 12-month periods count.

Example: 2 full years late = 20% × $202.90 = $40.58/month extra (about $486.96 per year), added to your premium for life and recalculated as the premium changes each year.

Part B penalty reference (2026 premium $202.90)

Part D late enrollment penalty

If you go without Part D or other creditable prescription drug coverage for any continuous period of 63 days or more after your Initial Enrollment Period, you may owe a penalty for as long as you have Part D. "Creditable coverage" means drug coverage expected to pay at least as much as Medicare's standard drug coverage — many, but not all, employer plans qualify.

How it's calculated: 1% of the national base beneficiary premium × the number of full uncovered months, rounded to the nearest $0.10. The 2026 national base beneficiary premium is $38.99/month.

Example: 29 uncovered months = 1% × $38.99 × 29 = $11.31, rounded to $11.30/month, added to your Part D premium and recalculated each year.

Part D penalty reference (2026 base premium $38.99)

Penalty amounts change every year as the national base beneficiary premium is updated.

How to avoid late enrollment penalties

• Enroll during your Initial Enrollment Period — the 7-month window that begins 3 months before the month you turn 65 and ends 3 months after.
• Use a Special Enrollment Period. If you have qualifying employer coverage, you generally have 8 months after it ends to enroll in Part A/B without penalty.
• Keep creditable drug coverage. For Part D, don't go 63+ days without creditable prescription drug coverage.
• If you get premium-free Part A, there's no Part A penalty to worry about.

Talk to a licensed iHealthAgents advisor — free

Our team can review your enrollment history, check whether a Special Enrollment Period or creditable-coverage exception applies, and help you sign up the right way.

• Illinois: 312-726-6565
• Texas: 972-666-0578

For educational use only. Estimates use 2026 figures: standard Part B premium $202.90, Part D national base beneficiary premium $38.99, and Part A premiums of $0 / $311 / $565. These amounts change annually, and your actual penalty is determined by Medicare and the Social Security Administration based on your records. Confirm your situation at 1-800-MEDICARE, with Social Security at 1-800-772-1213, or with a licensed iHealthAgents advisor. iHealthAgents is not connected with or endorsed by the U.S. government or the federal Medicare program.