Ask the Expert: Taking Medicare at 65 or 70?

I'm 63, and divorced. Can I wait until I'm 70 to collect Medicare, or must I take it when I reach 65? My ex-spouse will pay for my health insurance until the day that I receive Medicare. 

Better double-check the terms of your divorce settlement and the fine print in your current health insurance policy.

You may find that your ex agreed to pay for your health coverage until you become eligible for Medicare. Moreover, your current policy may require that Medicare become your primary carrier when you turn 65 -- a standard requirement in individual policies and employer --sponsored coverage at companies with fewer than 20 employees.

Other health coverage then becomes secondary. If Medicare covers 80 percent of a bill, for example, a secondary carrier might pay the 20 percent balance, after any deductible and co-payments. If your policy becomes secondary when you're 65 and you haven't signed up for Medicare, you must pay the primary share of the bill yourself.

And you can't sign up anytime you want. There are three enrollment periods. Initial Enrollment starts three months before and ends three months after, your 65th birthday. Special Enrollment starts when you retire, and ends eight months after your retirement date or the day your employer-sponsored coverage ends, whichever comes first.

If you miss those two enrollments, you can sign up during annual General Enrollment between Jan. 1 and March 31. But the longer you wait after your Special Enrollment period ends, the higher your premium. You pay an extra 10 percent for each 12 months of delay. If you sign up two years after Special Enrollment ended, for example, your Medicare Part B premium will always be 20 percent higher.

The bottom line: It's essential to learn how Medicare coordinates with your current coverage.

Click here for the Medicare bulletin on this topic.