Ask the Expert: Applying for Medicare

Your Jan. 28 column wasn't quite accurate about Medicare. You're not required to sign up for Medicare if you continue working past age 65. Once you stop working, you have an eight-month window to enroll in Medicare without incurring a penalty.

You're partly right, but it's more complicated than that.

As I wrote in the earlier column, you won't receive a Medicare enrollment notification at 65 unless you're collecting Social Security. I advised readers to call Medicare and sign up at 65 to avoid the late enrollment penalty, which is a permanently higher premium. You're right that you don't have to do this if you're currently covered by an employer with 20 or more employees for whom you or your spouse is actively working. In that case, your Medicare enrollment deadline is eight months after the termination of your employer-sponsored coverage or your job, whichever comes first.

But if neither you nor your spouse is actively working for the company, or if it employs fewer than 20 people, your employer's health plan becomes secondary to Medicare as soon as you turn 65. To avoid losing primary coverage and paying a late enrollment penalty, you must sign up for Medicare no later than three months after your 65th birthday. People often miss that deadline, says Joe Baker, president of the Medicare Rights Center, a nonprofit advocacy group. One reason is that small employers sometimes kindly but mistakenly assure older workers they can stay in the company plan. When people do this and the insurer later discovers they're Medicare-eligible, Baker says, it can bill them for reimbursement of the claims it has paid since they turned 65.

The bottom line: At least three months before turning 65, call your insurer and Social Security and ask them how your employer-sponsored plan coordinates with Medicare.

Websites with more information: 1.usa.gov/bnZwUe and 1.usa.gov/ymfiF3