Medicare Part A
Most people don’t pay a premium for Part A, but those who do may be penalized if they sign up after their IEP. The penalty is an additional 10% of the premium amount. It’s charged every month for twice the number of years enrollment was delayed.
Medicare Part B
Part B charges a penalty when you enroll after your IEP, unless you qualify for a Special Enrollment Period. The penalty is an additional 10% of the premium amount for each full 12-month period enrollment is delayed. It’s charged every month for as long as you have Part B.
Medicare Part D
The penalty for late enrollment in a Part D plan is 1% of the average Part D premium for each month you delay enrollment. You pay the penalty for as long as you’re enrolled in a Medicare Part D plan. You may delay enrolling in Medicare Part D without penalty if you qualify for Extra Help or have creditable drug coverage.
Medicare Supplement Insurance
You may apply for Medicare supplement insurance any time, even after your Open Enrollment Period. But you could be denied coverage or charged a higher premium based on your health history.