Not affiliated with AHIP/CMS/Medicare; educational only, not insurance advice
Estimate your 2026 Part D penalty
CMS-verified national base beneficiary premium: $38.99 for 2026. This is not your plan premium. Formula: 1% × $38.99 × full uncovered months, rounded to the nearest $0.10.
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Use your browser’s Print dialog and choose Save as PDF. Large-print output includes your current entries, results, assumptions and sources. Blank fields remain blank; enter 0 only when a cost is truly zero.
Count only eligible uncovered months
A penalty may apply after 63 consecutive days without Part D or other creditable drug coverage following your initial enrollment period. Count full uncovered months, not days divided by 30. Do not include creditable-coverage months; keep coverage notices. People qualifying for Extra Help do not pay this penalty. A health plan’s existence alone does not prove its drug coverage is creditable.
Your plan determines whether you owe a penalty and notifies you of the amount. Contact the plan about a disputed count and reconsideration instructions. The penalty generally lasts while you have Medicare drug coverage and may change with each year’s base premium. It is separate from the plan premium and IRMAA. Example: 14 uncovered months → $5.4586 → $5.50 per month, or $66.00 for 12 months at this rate.
The linked CMS partner PDF supplies procedural background and older examples; its historical premium figures are not used. The current 2026 CMS fact sheet supplies this calculator’s base.
Official sources
Rules and figures as of October 11, 2026. Calculators use 2026 amounts only; do not use them as 2027 estimates.
- https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties
- https://www.cms.gov/newsroom/fact-sheets/2026-medicare-part-d-bid-information-and-part-d-premium-stabilization-demonstration-parameters
- https://www.medicare.gov/health-drug-plans/part-d/basics/costs
- https://www.cms.gov/Outreach-and-Education/Outreach/Partnerships/downloads/11222-P.pdf