Creditable prescription drug coverage is any plan that pays, on average, at least as much as the standard Medicare Part D benefit. Employer plans, union plans, retiree plans, FEHB, VA benefits, and TRICARE usually qualify, and each year the plan sponsor must send you a notice saying yes or no, due before October 15. While you hold that coverage, you can skip Part D at 65 without penalty. The trouble starts the day the coverage ends. Medicare counts every full month you go 63 days or more in a row without creditable coverage or Part D, and charges 1% of the national base beneficiary premium for each one. In 2026 that base premium is $38.99, so 12 uncovered months adds about $4.70 per month to your Part D premium, and 36 months adds about $14.00 per month, every month for the rest of your life. Those amounts look small, but the penalty never expires and grows each year with the base premium. In 2026 the Part D out-of-pocket cap is $2,100, so a plan is worth having even if you take few drugs.
Losing creditable coverage at 65 usually happens in one of four ways: you retire, your employer changes or drops its retiree drug plan, your spouse's job ends, or COBRA runs out. Each one is a qualifying life event that opens a Part D Special Enrollment Period (SEP) of 2 months, so you do not need to wait for the Annual Election Period on October 15 through December 7, 2026. Part B works on a separate clock: the Part B SEP gives you 8 months after your job or group coverage ends, and COBRA does not count as coverage for that purpose. Some people lose a Marketplace plan instead, and a Marketplace plan with a Form 1095-A does not delay Medicare. Medicare Part A eligibility ends your premium tax credit, and the 2026 return of the 400% FPL subsidy cliff makes it costly to keep it. Medicare.gov, SSA.gov, and CMS.gov publish the rules, and KFF tracks how many people face penalties. This page gives the dates, the penalty math, the documents, and the six steps that keep your gap under 63 days.
6 Steps to Get Coverage
Common Mistakes That Cost People Thousands
Most Part D penalties in 2026 come from five avoidable errors made in the weeks right after creditable coverage ends.
- Assuming COBRA protects you from Part B penalties. COBRA keeps your drug plan going but does not give a Part B Special Enrollment Period, so enroll in Part B inside the 8-month SEP.
- Never confirming that the old plan was creditable. Without the written Notice of Creditable Coverage, Medicare can count every month as uncovered.
- Waiting for the Annual Election Period on October 15 through December 7, 2026. The 2-month Special Enrollment Period is faster, and the 63-day gap keeps running.
- Counting a discount card or a drug coupon program as coverage. GoodRx-type cards, health sharing ministries, and most Marketplace plans do not stop the gap.
- Ignoring the penalty letter. Medicare gives you 60 days to request reconsideration, and your plan will send an attestation form to answer within 30 days.
How the Part D Late Enrollment Penalty Is Calculated in 2026
The Part D late enrollment penalty equals 1% of the national base beneficiary premium multiplied by the number of full months you went without creditable coverage, rounded to the nearest $0.10. For 2026 the national base beneficiary premium is $38.99 per CMS. A 12-month gap adds about $4.70 per month, a 24-month gap adds about $9.40 per month, and a 48-month gap adds about $18.70 per month. Medicare adds the penalty to your premium for as long as you have Part D, including through plan changes. The months count only after your Initial Enrollment Period ends and only when the gap reaches 63 days in a row, so a 62-day gap carries no penalty at all. Medicare Advantage plans with drug coverage follow the same rule, and Medicaid, VA, and TRICARE drug benefits count as creditable coverage when they are in force. For example, a person who retires at 65 and waits 18 months before enrolling in Part D owes about $7.00 more per month in 2026 (18% of $38.99, rounded), and that amount follows them into every future plan.
Documents That Prove Your Coverage Was Creditable in 2026
Documents decide most penalty disputes, because Medicare sends a creditable coverage attestation form to your plan after you enroll and counts any month you cannot prove. The Notice of Creditable Coverage from your employer, union, or retiree plan is the key document, and it must show the plan name and the dates coverage ran. A termination letter or COBRA notice shows the exact end date, which anchors your 63-day count. Pay stubs or a retirement letter document the 8-month Part B Special Enrollment Period. Form CMS-L564 proves group health coverage through active employment, and Form CMS-40B starts the Part B application. Keep copies for at least 3 years, because penalty notices can arrive months after you enroll, and the 60-day reconsideration window starts on the date of the notice. Medicare.gov and SSA.gov both accept scanned copies, so photograph each letter the day it arrives.
Extra Help and Medicaid Can Remove the Part D Penalty in 2026
Extra Help, also called the Low-Income Subsidy, removes the Part D late enrollment penalty entirely for people who qualify. For 2026, the income limit is 150% of the Federal Poverty Level, which is $23,940 for one person and $32,460 for a married couple, plus a resource test. People with full Medicaid or a Medicare Savings Program are enrolled in Extra Help automatically. Medicaid pays for drugs in every state, and state brands include Medi-Cal in California, AHCCCS in Arizona, MassHealth in Massachusetts, and BadgerCare in Wisconsin. In the 40 expansion states plus DC, the adult Medicaid line is 138% FPL, or $22,025 for one person in 2026, but people 65 and older are often assessed under separate aged-and-disabled rules with their own limits. A spouse under 65 or a child may qualify for CHIP or Medicaid even when you are on Medicare. Apply at ssa.gov/extrahelp or at your state Medicaid agency, which Medicaid.gov lists for every state.
Frequently Asked Questions
What is the Part D Special Enrollment Period after losing creditable coverage?
You get a Special Enrollment Period of 2 months after the month your creditable drug coverage ends, or after the month you are notified, whichever is later. If coverage ends November 30, 2026, your SEP runs December 1, 2026 through January 31, 2027. Enroll in a Part D plan or Medicare Advantage plan with drugs through Medicare.gov or 1-800-MEDICARE during that window. A plan that starts by February 1, 2027 keeps your gap at 62 days, one day short of the 63-day penalty trigger. This SEP applies only when you lose coverage involuntarily, such as when an employer drops a plan or you lose a job.
How much is the Part D late enrollment penalty in 2026?
The 2026 penalty is 1% of the $38.99 national base beneficiary premium for each full month you went 63 days or more without creditable coverage, rounded to the nearest $0.10. A 12-month gap adds about $4.70 per month, and a 24-month gap adds about $9.40 per month. Medicare adds the amount to your Part D premium every month for as long as you have Part D coverage. The base premium changes each year, so the dollar amount grows over time even though your months uncovered stay the same.
How do I document that my coverage was creditable?
Ask your plan administrator or HR for a written Notice of Creditable Coverage showing the plan name, that its drug coverage is creditable, and the dates it ran. Employers must send this notice every year before October 15 and give it on request. Also keep your termination letter or COBRA notice for the exact end date. After you enroll in Part D, Medicare may mail an attestation form asking about your prior coverage, and you have 30 days to answer. Keep copies for at least 3 years in case a penalty notice arrives later.
What if I miss the Part D Special Enrollment Period?
You can still enroll during the Annual Election Period, October 15 through December 7, 2026, for coverage starting January 1, 2027. The penalty clock keeps running until your plan starts, and each uncovered month after Day 63 adds 1% of the national base premium to your lifetime penalty. If your income is under 150% FPL ($23,940 for one person in 2026), apply for Extra Help, which waives the penalty. You can also request reconsideration if you had a reason for the gap, such as incorrect advice from your employer.
Can I get retroactive Part D coverage after losing creditable coverage?
Part D coverage generally starts the first day of the month after your plan receives your enrollment, so it is not retroactive. The exceptions are Extra Help and Medicaid, where Medicare can sometimes apply coverage back to the month you became eligible. Because most Part D coverage is not retroactive, enroll early in your Special Enrollment Period. Enrolling in the first month of the window starts coverage the next month and leaves the shortest possible gap.
What is the difference between COBRA and Medicare Part D after losing coverage at 65?
COBRA continues your old plan at 102% of the full premium, often $400 to $900 per month in 2026, and may include creditable drug coverage. Medicare Part D is cheaper for most people, and an out-of-pocket cap of $2,100 applies in 2026. COBRA does not give you a Part B Special Enrollment Period, so a Part B penalty of 10% per 12-month period can start while you wait. If you keep COBRA, enroll in Part B inside your 8-month window, and get written confirmation that your COBRA drug coverage is creditable.
What state-specific rules apply when I lose creditable coverage?
Federal rules set the 63-day gap and the Part D penalty in all states, but state programs can help. Every state has a SHIP counselor for free help, and states such as New York (EPIC), Pennsylvania (PACE and PACENET), and New Jersey (PAAD) run drug assistance programs that work alongside Part D. Medicaid brands also vary: Medi-Cal in California, AHCCCS in Arizona, MassHealth in Massachusetts, and BadgerCare in Wisconsin. Check with your state agency to confirm whether its drug program counts as creditable coverage.
Do I qualify for Medicaid or Extra Help after losing creditable coverage?
Extra Help covers people with a 2026 income under 150% FPL, which is $23,940 for one person and $32,460 for a couple, subject to a resource limit. Full Medicaid in expansion states uses a 138% FPL line, about $22,025 for one person in 2026, though people 65 and older may be assessed under aged-and-disabled rules. Both programs pay Part D costs and Extra Help waives the late enrollment penalty. Apply at ssa.gov/extrahelp or at your state Medicaid agency, and apply early because Medicaid is year-round.
