The Part D late enrollment penalty is a permanent addition to your drug plan premium, charged if you go 63 or more days in a row without Medicare drug coverage or other creditable coverage after your first enrollment window ends. It is 1 percent of the national base premium for every month you went without coverage, and it is added to your premium for as long as you have Part D.
How the math works
The national base beneficiary premium for 2026 is $38.99. Each month without coverage adds 1 percent of that, about 39 cents, rounded to the nearest ten cents. Two years without coverage is 24 months, so 24 percent of $38.99, about $9.40 added to your premium every month for life. The base premium changes each year, so the penalty changes with it.
"I don't take any drugs"
This is the most common reason people skip Part D, and it is the most common reason they pay the penalty later. Enrolling in a low-premium drug plan when you first qualify, even one you never use, protects you. Some plans cost under $10 a month. That is cheaper than a lifetime penalty plus the risk of needing an expensive drug with no coverage until the next enrollment period.
Creditable coverage stops the clock
Coverage from an employer, a union, the VA, TRICARE or a federal employee plan counts if the plan says it is creditable, meaning at least as good as standard Part D. Your plan sends a notice each fall. Keep every one of those letters. When you eventually enroll in Part D, the plan may ask you to prove you had coverage, and the letters are the proof.
If you already have the penalty
You can ask for a reconsideration if you believe the count is wrong or you had creditable coverage the plan did not know about. The request form comes with the penalty letter and has a 60-day deadline.
Turning 65 or leaving a job plan soon? Request a plan check and I match a drug plan to your prescriptions and your pharmacy before the clock starts.