| Uncovered months | 2026 (base $38.99) | 2027 (base $41.33) | Extra cost in 2027, per year |
|---|---|---|---|
| 3 | $1.20 | $1.20 | $14.40 |
| 6 | $2.30 | $2.50 | $30.00 |
| 12 | $4.70 | $5.00 | $60.00 |
| 18 | $7.00 | $7.40 | $88.80 |
| 24 | $9.40 | $9.90 | $118.80 |
| 36 | $14.00 | $14.90 | $178.80 |
| 60 | $23.40 | $24.80 | $297.60 |
| 120 | $46.80 | $49.60 | $595.20 |
Medicare's formula: 1% × national base beneficiary premium × full uncovered months, rounded to the nearest $0.10. This is an estimate; the official figure comes in your plan's penalty letter. The math runs in your browser and nothing is stored.
How Medicare calculates the penalty
The Part D late enrollment penalty is an extra charge added to your monthly drug plan premium if, after your Initial Enrollment Period, you went 63 or more days in a row without Part D or other creditable prescription drug coverage. Medicare’s fact sheet gives the formula in one line: 1% times the national base beneficiary premium times the number of full months without coverage, with the result rounded to the nearest $0.10.
Medicare’s own example: a man went 17 months without creditable coverage, from August 1, 2024 to December 31, 2025, and his new plan started January 1, 2026. His penalty is 17% of $38.99, which is $6.63, rounded to $6.60 a month. The calculator above reproduces that arithmetic and adds the 2027 figure.
Two details change the count. Only full months count, so a partial month at either end does not add a percent. And the clock starts after your Initial Enrollment Period ends, not on your 65th birthday. Medicare in New York: the basics.
The 2026 and 2027 base premiums
| Year | National base beneficiary premium | 12 uncovered months | 24 uncovered months | 60 uncovered months |
|---|---|---|---|---|
| 2026 | $38.99 | $4.70 a month | $9.40 a month | $23.40 a month |
| 2027 | $41.33 | $5.00 a month | $9.90 a month | $24.80 a month |
CMS announced the 2027 base premium of $41.33 on July 28, 2026, alongside a national average monthly bid amount of $296.05. The base premium is a benchmark used in Part D pricing, not what any plan charges, and its only role on your bill is this penalty.
Because the base premium changes every year, the penalty changes every year too. Your percentage stays fixed: someone with a 17% penalty pays 17% of $38.99 in 2026 and 17% of $41.33 in 2027. That is why a penalty that looks small at sign-up grows over a retirement. If you are joining a plan for January 2027, the 2027 figure is the one your first bill will use.
What counts as creditable coverage
Creditable prescription drug coverage is drug coverage expected to pay, on average, at least as much as Medicare’s standard drug coverage. Medicare lists examples: coverage from a current or former employer or union, TRICARE, the Indian Health Service, a Tribe or Tribal organization, an Urban Indian program, and other health plans.
The plan must tell you in writing whether its coverage is creditable. Most people get that notice once a year from a retiree or employer plan, and it is the document that protects you later. Keep it with your Medicare papers.
| Your situation | Does it stop the penalty clock? |
|---|---|
| Job-based or union drug coverage with a creditable notice | Yes |
| Retiree plan with a creditable notice | Yes |
| Drug coverage that is not creditable, or no notice at all | No; ask the plan in writing |
| No drug coverage, but you got Extra Help in those months | Those months do not count toward a penalty |
| A gap of fewer than 63 days in a row | No penalty for that gap |
When you join a Part D plan, the plan checks Medicare’s records for a break of 63 days or more. If it finds one, it sends you a form about prior coverage. Return it by the deadline printed on it: that form is your chance to show coverage Medicare did not know about.
Extra Help: the one way to make it disappear
If you qualify for Extra Help, the federal program that lowers Part D premiums, deductibles and copays, you are not charged a late enrollment penalty while you get it. Medicare also does not count the months before you qualified for Extra Help toward a penalty.
That makes Extra Help worth checking before you pay any penalty. Medicare gives Extra Help automatically to people with full Medicaid, Supplemental Security Income or a Medicare Savings Program, QMB or QI, and the state’s 2026 limits are $1,836 a month for QMB and $2,474 for QI for one person, with no asset test. The Medicare Savings Program calculator checks your number in a minute. How Extra Help works.
The weak spot: Extra Help protects you while you have it. Medicare’s fact sheet says that if you later drop drug coverage, go 63 days or more without it and no longer qualify for Extra Help, a penalty can be charged when you rejoin.
If you think the penalty is wrong
- Find the letter. Your plan sends a notice saying you owe a late enrollment penalty, with a reconsideration form inside.
- Return the form within 60 days of the date on the letter, to the address or fax number on it. A late form needs a written explanation of why it is late.
- Attach proof. The strongest proof is a creditable coverage notice from an employer, union or retiree plan for the months in question.
- Keep paying. By law the penalty is part of the premium, and a plan can disenroll you for unpaid premiums, including the penalty, even while a reconsideration is pending.
- Wait for the decision. A Medicare contractor not connected with your plan decides, generally within 90 days. If it rules the penalty wrong, the plan removes or adjusts it and explains any refund.
Switching to a different plan is not a reason to ask for reconsideration: the penalty travels with you. New York’s free Medicare counseling program, HIICAP, helps with the letter and the form at no cost, and the state’s EPIC program is worth checking for drug costs at the same time.
Where this calculator stops
The calculator applies Medicare’s formula to the months you enter. It cannot see Medicare’s records, so it does not know about creditable coverage you forgot, months covered by Extra Help, or a mistake in your enrollment dates. The penalty letter from your plan is the official number; this is the arithmetic to check it against.
It also covers only Part D. Part B has its own late penalty with separate rules and its own sign-up window. The General Enrollment Period and the Part B penalty.
Questions people ask
How is the Part D late enrollment penalty calculated?
Medicare multiplies 1% by the national base beneficiary premium and by the number of full months you went without Part D or creditable drug coverage, then rounds to the nearest $0.10. In 2026 the base premium is $38.99; in 2027 it is $41.33.
What is the Part D base beneficiary premium for 2027?
$41.33, announced by CMS on July 28, 2026. The 2026 figure is $38.99.
Is the Part D penalty permanent?
Generally yes. You pay it for as long as you have Medicare drug coverage, even if you switch plans or join a $0 premium plan. The dollar amount is recalculated each year with the new base premium.
Do I pay the penalty if I get Extra Help?
No. People who qualify for Extra Help are not charged the late enrollment penalty while they get it, and months before they qualified do not count toward one.
How long do I have to appeal a Part D late enrollment penalty?
Return the reconsideration form within 60 days of the date on the letter that says you owe the penalty. Keep paying the penalty while you wait for a decision.
Sources
- Medicare.gov — The Part D Late Enrollment Penalty, fact sheet, CMS Product No. 11222 (July 2026) (checked 2026-11-03)
- Medicare.gov — Costs for Medicare drug coverage (checked 2026-11-03)
- CMS — Medicare Part D 2027 national average monthly bid amount information (fact sheet, July 28, 2026) (checked 2026-11-03)
- Medicare.gov — Help with drug costs (Extra Help) (checked 2026-11-03)
- NYS Department of Health — GIS 26 MA/05, Attachment I: 2026 Medicaid income and resource standards (QMB, QI) (checked 2026-11-03)
More in Medicare in New York: What the Fall Season Actually Decides
- Medicare Part B Premium and IRMAA for New Yorkers: 2026 Brackets, 2027 Status — The 2027 Part B premium was not out on Oct 29, 2026. In 2026 it is $202.90, and IRMAA starts above $109,000 single or $218,000 joint. How to lower it.
- Medicare Home Health Care in New York: Who Qualifies, What It Costs, How to Find an Agency — Medicare home health care costs $0 if you are homebound and need part-time skilled care, under 8 hours a day. What it skips and who pays in New York.
- Medicare Appeals and the ABN in New York: What the Notice Means and How to Fight a Denial — An ABN (Advance Beneficiary Notice) warns that Original Medicare may not pay. Which option to check, how to appeal, the deadlines and the fast discharge appeal.
This page explains how the system works. It is not medical advice. More.