The late enrollment penalty is an amount that’s added to your Part D premium if, at any time after your Part D Initial Enrollment Period is over, there’s a period of 63 or more days in a row when you don’t have Part D or other creditable prescription drug coverage.
How much is the late enrollment penalty?
Currently, the penalty amount is calculated by multiplying the 1% penalty rate times the “national base beneficiary premium” ($35.02 in 2018) times the number of full, uncovered months you were eligible to join a Medicare drug plan but didn’t and went without other creditable prescription drug coverage. The final amount is rounded to the nearest $.10 and added to your monthly premium. The “national base beneficiary premium” may go up each year, so the penalty amount may also increase each year. In addition to your premium each month, you may have to pay this penalty for as long as you have a Medicare drug plan.