Medicare Late Enrollment Penalty Calculator

Missing your Medicare sign-up window can mean a penalty that lasts as long as you have coverage. Enter how long you went without coverage to estimate it.

months
Don’t count months you had job-based coverage from current work.
months
Count months after your window ended without Part D or other creditable drug coverage.

How the penalties work

Part B penalty = 10% × number of full 12-month periods late × standard premium ($202.90 in 2026)
Part D penalty = 1% × months without coverage × national base premium ($38.99 in 2026), rounded to the nearest $0.10

Example

If you waited 2 full years after your window closed to get Part B, your penalty is 20%. In 2026 that’s about $40.58 extra every month, on top of the standard premium, for as long as you have Part B.

How to avoid penalties

  • Sign up during your Initial Enrollment Period around age 65.
  • If you’re still working with job-based insurance, ask whether it’s “creditable” and keep proof; you can sign up later without penalty.
  • Keep some kind of creditable drug coverage once you’re eligible, even if you take few medicines.
  • People with limited income may qualify for Extra Help, which removes the Part D penalty.
Estimate only. For official answers, visit Medicare.gov, call 1-800-MEDICARE (1-800-633-4227), or contact your free State Health Insurance Assistance Program (SHIP).

Frequently asked questions

How much is the Medicare Part B late penalty?

10% of the standard premium for each full 12-month period you could have had Part B but didn’t. In 2026 the standard premium is $202.90, so each 10% adds about $20.29 a month.

Does the Medicare penalty ever go away?

For most people, no. The Part B and Part D penalties are usually added for as long as you have coverage.

What counts as creditable drug coverage?

Drug coverage expected to pay, on average, at least as much as standard Medicare drug coverage, such as many employer or VA plans. Your plan must tell you each year.

Sources

  • Centers for Medicare & Medicaid Services – 2026 Medicare Parts A & B premiums and deductibles (Federal Register, Nov 19, 2025)
  • Medicare.gov – Avoid late enrollment penalties
  • CMS – 2026 Part D national base beneficiary premium

Last reviewed: November 2026 · By the GoldenYearsTools team at XplainedDaily · How we build our tools