# What is my Part D penalty?

Works out the Medicare Part D late enrollment penalty: 1% of the national base premium for each month you went without drug coverage, for 2026 or 2027.

- Page: https://www.acalculator.org/finance/part-d-penalty-calculator
- JSON spec: https://www.acalculator.org/finance/part-d-penalty-calculator.json
- Version: 02ea60ac77da

## Default answer

Example with the default inputs (Months without drug coverage 14, Year 2026): With 14 months without drug coverage, your Part D penalty is $5.50 a month in 2026.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| months | Months without drug coverage | Full months after your first chance to join Part D with no Part D plan and no other creditable drug coverage (gaps of 63 days or more). |
| year | Year | The penalty is worked out again each year from that year’s base premium. |
| plan | Your plan’s monthly premium | Optional: your drug plan’s premium, to see the total you pay each month. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| monthly | Penalty a month | Months × 1% × the national base premium, rounded to the nearest 10 cents. |
| percent | Penalty percent | One percent for each month without coverage. |
| base | National base premium | The national base beneficiary premium for the year, per month. |
| yearly | Penalty a year | The monthly penalty times 12. |
| total | Total premium a month | Your plan premium plus the penalty. |

## Method

Penalty a month = months without coverage × 1% × national base beneficiary premium ($38.99 in 2026, $41.33 in 2027), rounded to the nearest $0.10.

## Assumptions

- Only full months count, from the end of your initial enrollment period (or the end of your last creditable coverage) to when your Part D coverage starts.
- A gap of fewer than 63 days in a row adds no penalty.
- People who get Extra Help pay no late enrollment penalty.
- Medicare decides the count of months; this page uses the number you enter.

## Worked examples

1. months = 14, year = 2026 gives percent = 14%, base = $38.99, monthly = $5.50, yearly = $66.00. Source: Medicare.gov, Avoid late enrollment penalties (https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties): $38.99 × 0.14 = $5.46, rounded to the nearest $0.10 = $5.50.
2. months = 25, year = 2026, plan = $45.50 gives monthly = $9.70, yearly = $116.40, total = $55.20. Source: Medicare.gov rule (1% a month of $38.99, nearest $0.10): 38.99 × 0.25 = 9.7475, $9.70.
3. months = 14, year = 2027 gives base = $41.33, monthly = $5.80, yearly = $69.60. Source: CMS fact sheet, July 28, 2026 (https://www.cms.gov/newsroom/fact-sheets/medicare-part-d-2027-national-average-monthly-bid-amount-information): 2027 base premium $41.33.
4. months = 500, year = 2026 gives monthly = $195.00.
5. months = 0, year = 2026, plan = $12.00 gives monthly = $0.00, total = $12.00. Source: Medicare.gov: no months without creditable coverage means no penalty.

## FAQ

### How is the Part D late enrollment penalty calculated?

Medicare multiplies 1% of the national base beneficiary premium by the number of full months you went without Part D or other creditable drug coverage, and rounds to the nearest $0.10. Fourteen months in 2026 is 38.99 × 0.14 = $5.46, so $5.50 a month.

### What is the national base beneficiary premium for 2026?

It is $38.99 a month for 2026. CMS set it at $41.33 for 2027.

### How long do I pay the Part D penalty?

Usually for as long as you have Medicare drug coverage, even if you change plans. The penalty is worked out again each year from that year’s base premium, so the dollar amount can change.

### How long can I go without drug coverage before a penalty?

A gap of 63 days or more in a row without Part D or other creditable coverage, after your initial enrollment period ends, starts the penalty. Shorter gaps do not count.

### Can I avoid or remove the penalty?

People who qualify for Extra Help do not pay it. If you think Medicare counted months when you had creditable coverage, you can ask for a reconsideration.

## Sources

- Medicare.gov, Avoid late enrollment penalties: https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties (retrieved 2026-10-05)
- Centers for Medicare & Medicaid Services, 2026 Medicare Part D Bid Information and Part D Premium Stabilization Demonstration Parameters (July 28, 2025): https://www.cms.gov/newsroom/fact-sheets/2026-medicare-part-d-bid-information-and-part-d-premium-stabilization-demonstration-parameters (retrieved 2026-10-05)
- Centers for Medicare & Medicaid Services, Medicare Part D 2027 National Average Monthly Bid Amount Information (July 28, 2026): https://www.cms.gov/newsroom/fact-sheets/medicare-part-d-2027-national-average-monthly-bid-amount-information (retrieved 2026-10-05)