By Marc Gilman
📞 (800) 927-9326 |
If you delayed enrolling in a Medicare Part D prescription drug plan — or went without creditable drug coverage for an extended period — you may be facing a penalty that follows you for life. The Part D late enrollment penalty is one of the most misunderstood costs in Medicare, and one of the most avoidable.
Here’s exactly how it works, how it’s calculated, and what to do if you believe yours was assessed incorrectly.
Key Takeaways
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The Part D late enrollment penalty is a permanent monthly surcharge added to your Part D premium for as long as you have Medicare drug coverage.
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The penalty applies if you go 63 or more consecutive days without Part D or creditable prescription drug coverage after your Initial Enrollment Period ends.
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The penalty equals 1% of the national base beneficiary premium for every uncovered month, rounded to the nearest $0.10.
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The dollar amount recalculates every year as the base premium changes — but your penalty percentage stays fixed.
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The 2026 base beneficiary premium is $38.99. The 2027 projected base is $41.33 — meaning the same penalty will cost more in dollars next year.
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Extra Help (Low Income Subsidy) recipients do not pay a late enrollment penalty while they qualify.
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If you believe your penalty is incorrect, you can request a reconsideration within 60 days of the penalty notice.
What Is the Part D Late Enrollment Penalty?
When you first become eligible for Medicare, you have a window — called your Initial Enrollment Period — to sign up for Part D prescription drug coverage or maintain other creditable drug coverage. If you miss that window and go without coverage for 63 or more consecutive days, Medicare charges you a late enrollment penalty when you eventually do enroll.
The penalty isn’t a one-time fee. It’s a monthly surcharge permanently added to your Part D premium, every month, for as long as you have Medicare drug coverage. It follows you even if you switch plans. It even applies if your current plan has a $0 monthly premium — in that case, you still pay the penalty amount each month even though you pay nothing for the plan itself.
The Formula
Medicare calculates the penalty as follows:
Penalty = 1% × national base beneficiary premium × number of uncovered months
The result is rounded to the nearest $0.10.
That’s it. Three numbers. But the implications add up quickly.
The Base Beneficiary Premium — and Why It Matters
The “national base beneficiary premium” is a benchmark figure CMS sets each year. It’s not what you pay for your specific plan — it’s the number used to calculate penalty amounts across all Part D plans.
Historical and projected base premiums:
Your penalty percentage is fixed the moment it’s assessed — but the dollar amount recalculates every January when the new base premium is published. As the base premium rises, the same penalty percentage costs more money.
This is why it matters that CMS is projecting a base premium of $41.33 for 2027 — a 6% increase from 2026. Someone with a 24% penalty paid $8.33/month in 2024. In 2026 they pay $9.36/month. In 2027 they’ll pay roughly $9.91/month — for the exact same gap in coverage that happened years ago.
Worked Examples
Example 1: 24 Months Without Coverage (Mr. Ray)
Mr. Ray was enrolled in Part D but disenrolled effective December 31, 2021. He rejoined during AEP in Fall 2023, with coverage effective January 1, 2024. He went 24 full months — January 2022 through December 2023 — without creditable coverage.
Penalty calculation for 2024:
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24 months × 1% = 24% penalty
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24% × $34.70 (2026 base) = $8.33
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Rounded to nearest $0.10 = $8.30/month
In 2026, Medicare recalculates: 24% × $38.99 = $9.36, rounded to $9.40/month — same gap, higher dollar amount.
Example 2: 29 Months Without Coverage (Mrs. Martinez)
Mrs. Martinez’s Initial Enrollment Period ended July 31, 2020. She didn’t enroll and had no other creditable coverage. She enrolled during AEP in Fall 2022, with coverage effective January 1, 2023 — 29 uncovered months.
Penalty calculation for 2023:
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29 months × 1% = 29% penalty
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29% × $32.74 = $9.49
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Rounded to $9.50/month
In 2024, Medicare recalculated: 29% × $34.70 = $10.06, rounded to $10.10/month.
In 2026: 29% × $38.99 = $11.31, rounded to $11.30/month. The uncovered period never changed — the cost keeps climbing.
Example 3: Extra Help Exemption (Mrs. Kim)
Mrs. Kim’s Initial Enrollment Period ended July 2021. She didn’t enroll in Part D until October 2021 (effective January 1, 2022) — but she qualified for Extra Help, so the 5 uncovered months in 2021 were not counted.
She dropped her plan effective June 30, 2022. She still qualified for Extra Help through December 2022. She rejoined during AEP in Fall 2023, effective January 1, 2024.
What Medicare counts toward her penalty:
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The 5 months in 2021 before Extra Help: not counted (Extra Help was active)
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The 6 months in 2022 after dropping coverage: not counted (Extra Help was still active)
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The 12 months in 2023 without coverage and without Extra Help: counted
Penalty: 12% × $34.70 = $4.16, rounded to $4.20/month — only 12 months assessed, not 23.
The Extra Help exemption is significant: if you qualify for Extra Help, you don’t pay the penalty at all during that period, and those months aren’t factored into any future penalty calculation.
The 63-Day Rule
The penalty applies only if you go 63 or more consecutive days without Part D or creditable coverage after your Initial Enrollment Period ends.
A gap of 62 days or fewer doesn’t trigger a penalty. The 63rd consecutive day is what starts the clock.
If you had a brief transition — say, between losing employer coverage and enrolling in Part D — and that transition was 62 days or less, you’re in the clear. If it was 63 or more, the penalty begins at month 1 of that gap (counting only full calendar months).
What Counts as Creditable Coverage?
Creditable prescription drug coverage is coverage expected to pay, on average, at least as much as Medicare’s standard drug benefit. If you have creditable coverage from another source, you can delay Part D enrollment without penalty for as long as that coverage remains in effect.
Coverage that qualifies:
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Employer or union drug plans (must be certified as creditable by the employer)
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Federal Employees Health Benefits Program (FEHB)
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VA drug benefits
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TRICARE
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Qualified State Pharmaceutical Assistance Programs (SPAPs)
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Some Medigap plans (the older ones with drug coverage, pre-2006)
Coverage that does not qualify:
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Drug discount cards
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Medical coverage with no drug benefit
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A plan that hasn’t confirmed in writing that its coverage is creditable
Employers and plan sponsors are required by law to notify Medicare-eligible plan members each year — before October 15 — whether their drug coverage is creditable. If you’re still working and on an employer plan, you should receive this notice annually. If you don’t receive one, contact your HR department or plan directly.
What Happens When You Join a New Plan
When you enroll in a Part D plan, the plan checks Medicare’s records for any potential gaps of 63 or more consecutive days. If Medicare’s records show a potential gap, the plan will send you a notice asking about prior drug coverage. This is your opportunity to document coverage that may not be in Medicare’s systems — such as employer coverage, VA benefits, or TRICARE that wasn’t automatically reported.
Return this form by the deadline on the notice. If you miss it, the plan may assess a penalty based only on what Medicare’s records show — which may not include all your prior creditable coverage.
If You Disagree With Your Penalty
You have the right to request a reconsideration — a formal review by a Medicare contractor (not your plan) of whether the penalty was assessed correctly.
How the process works:
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Your plan sends you a written notice of the penalty. The notice includes an LEP Reconsideration Request Form.
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You have 60 days from the date on the notice to complete and return the form to the Medicare contractor listed on the form (by mail or fax).
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Medicare’s contractor makes a reconsideration decision generally within 90 days. In complex cases, the contractor may take an additional 14 days.
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You must continue paying the penalty during the review. Plans can disenroll members who don’t pay their premiums, including the penalty portion. You cannot withhold the penalty while waiting for a decision.
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If the contractor finds the penalty was incorrect — or your gap was shorter than recorded — the plan will reduce or remove the penalty and refund any penalty amounts you paid during the review period.
If you believe you had creditable coverage that wasn’t recorded in Medicare’s systems (employer coverage, VA benefits, TRICARE), gather documentation from that plan and submit it with your reconsideration request. A letter from your former employer confirming creditable drug coverage for specific dates is typically sufficient.
How to Avoid the Penalty
Enroll during your Initial Enrollment Period. The seven-month window around your 65th birthday is your best opportunity to enroll with no penalty and no questions.
Maintain creditable coverage continuously. If you have employer, FEHB, VA, or TRICARE coverage, verify in writing each year that it qualifies as creditable. Ask for the creditable coverage notice your employer is required to provide before October 15.
Enroll in Part D even if you take few medications. Many people skip Part D enrollment because they take no prescriptions or very cheap ones. A plan with a $0 monthly premium still satisfies the requirement — and avoids a penalty that will grow in dollar value every year the base premium rises.
Act immediately when employer or other creditable coverage ends. The SEP after losing creditable coverage runs for 63 days — after that, any additional days count toward a penalty. Don’t wait until the next AEP if your coverage is ending.
The 2027 Projection: Why This Year Matters
CMS projects the 2027 national base beneficiary premium will be $41.33 — an increase from $38.99 in 2026. This is connected to the end of the Part D Premium Stabilization Demonstration, which we covered in a recent post.
For anyone already paying a Part D late enrollment penalty, the 2027 base premium increase means their penalty will rise in dollar terms — even though the underlying gap in coverage happened years ago. A 24-month penalty currently costs $9.40/month (2026). In 2027 it will cost approximately $9.90/month.
This is why the penalty is never truly “settled” — it’s permanently tied to a figure that changes annually, and in recent years, that figure has been trending upward.
Have a Part D penalty on your account — or think one was assessed incorrectly? We help clients review their penalty history and, where appropriate, prepare reconsideration requests. Call or email anytime — there’s no charge.
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📰 Related: Is Your Medicare Part D Premium Going Up in 2027? · Medicare FAQ: Your Questions Answered · What Is Medicare Part D?
