Also called: creditable coverage
If you go 63 days or more after your initial enrollment without Part D or other creditable drug coverage, a permanent penalty of 1% of the national base premium per uncovered month is added.
Creditable coverage means drug coverage expected to pay at least as much as standard Part D. Employer and retiree plans must tell you each year whether their coverage is creditable.
The penalty is recalculated every year from the current national base beneficiary premium and lasts as long as you have Part D.