Part D late enrollment penalty

Generally, if you did not sign up for Part D coverage during your initial enrollment period, and you don't have other creditable drug coverage (at least comparable to Medicare's standard prescription drug coverage) for at least 63 days in a row after your initial enrollment period, you may have to pay a late enrollment penalty. The late enrollment penalty is added to your monthly Part D premium. Your initial enrollment period is the seven-month period that starts three months before you turn age 65 (including the month you turn age 65) and ends three months after the month you turn 65