Signing up late for Medicare can add a penalty to your monthly price for the rest of your life. Enter a few dates to see if you'd owe one, and how much. Nothing you type leaves this page.
How it works. For Part B, each full year you could have signed up but didn't adds 10% to your monthly price. Time on a job's health plan while still working doesn't count against you. For Part D, each month without drug coverage adds 1% of a set national amount, once you've gone without for more than 63 days. Both penalties last for life.