Medicare late enrollment penalties are designed to encourage people to sign up for coverage when they first become eligible. Unlike a one-time fine, these penalties are added to your monthly premiums, and in the case of Parts B and D, they generally last for as long as you have the coverage.

Medicare Part B Penalty (Medical Insurance)

This is the most common penalty and is often the most expensive over time because it is a permanent lifetime surcharge.

  • The Penalty: 10 percent of the standard monthly premium for each full 12-month period you were eligible but didn’t sign up.
  • 2026 Cost Example: The standard premium is $202.90. If you waited two full years to enroll, your penalty would be 20%, adding $40.60 to your monthly bill forever.
  • Duration: Lifetime. You pay it as long as you have Part B.

Medicare Part D Penalty (Drug Coverage)

This penalty applies if you go 63 days or more without “creditable” drug coverage (coverage as good as Medicare’s) after your initial window closes.

  • The Calculation: 1 percent of the “national base beneficiary premium” for every month you were without coverage.
  • 2026 Base Premium: $38.99.
  • 2026 Cost Example: If you went 24 months without coverage, your penalty would be 24% of $38.99, which is $9.40 per month.
  • Duration: Lifetime. This amount is rounded to the nearest $0.10 and added to your drug plan premium every month.

Medicare Part A Penalty (Hospital Insurance)

Most people do not pay a premium for Part A (and thus have no penalty) because they worked for at least 10 years. However, if you must buy Part A and miss your window:

  • The Penalty: A 10 percent increase in your monthly premium.
  • 2026 Cost Example: For the full premium of $565, the penalty adds $56.50 per month.
  • Duration: Limited. You pay this for twice the number of years you were late. If you were one year late, you pay the penalty for two years.

How to Avoid Penalties in 2026

You can bypass these extra costs if you meet specific criteria:

  • Initial Enrollment: Sign up during your 7-month Initial Enrollment Period when you turn 65.
  • Creditable Coverage: If you are still working for an employer with 20 or more employees, your employer’s health and drug plans are usually considered “creditable.” This allows you to delay Parts B and D without penalty until you retire.
  • Extra Help: If you qualify for the “Extra Help” program to pay for medications, your Part D late enrollment penalty is waived.

2026 Penalty Summary Table

Medicare PartPenalty AmountDuration
Part B10% per 12-month periodLifetime
Part D1% of base premium per monthLifetime
Part A10% of premium2x years delayed

Source: Medicare.gov, “Avoid Late Enrollment Penalties” (2026 Update); and Social Security Administration (SSA), “Medicare Premiums for 2026.”