I’m 64 and retired, but I won’t start collecting Social Security until I’m 70. Will that delay my Medicare eligibility? When should I apply for Medicare? Does it make a difference that I’ll have medical coverage through my former employer even after I start Medicare?

First things first. Enroll in Medicare a month before your 65th birthday to avoid any lapse in primary coverage.

To complicate life, Social Security and Medicare have entirely different schedules and rules. No matter when you start Social Security, your Medicare enrollment deadline is three months after your 65th birthday, unless you qualify for an exception. Medicare coverage starts a month after you enroll.

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If you miss your original deadline, your Medicare premiums may be permanently higher. Worse, you may temporarily be uninsured because your next chance to enroll won’t be until Medicare’s annual general enrollment. That’s between Jan. 1 and March 31 for coverage that starts on July 1.

So when do you qualify for an exception to the age 65 Medicare sign-up deadline? When you’re covered by a workplace plan from a company with 20 or more employees, for which you or your spouse actively work. In that case, your Medicare enrollment deadline is eight months after the job or the employer coverage ends, whichever comes first.

The key words are “actively work.” You’re retired, so unless your spouse still works for your former employer, you don’t qualify for the exception — which means that when you turn 65, your former employer’s plan becomes secondary to Medicare. A secondary insurer pays for expenses that aren’t covered by Medicare, like deductibles and coinsurance, but will no longer pay for services that Medicare covers.

THE BOTTOM LINE Delaying Social Security benefits doesn’t postpone your Medicare enrollment deadline.

WEBSITES WITH MORE INFORMATION nwsdy.li/MedcareSecond and nwsdy.li/MedicareInfo