I became eligible for Medicare last December and took Part A, but declined Part B to save money. I’m insured through my husband, a city retiree. Recently, I received a $1,300 lab bill for routine blood work and learned that after age 65, our plan only covers 20 percent of medical bills and we need Medicare Part B as primary coverage. But I’m told I can’t enroll for Part B until General Enrollment, between Jan. 1 and March 31, 2018, and the coverage wouldn’t start until July 2018. Do we have any options until then?

Your situation is a sad example of what can happen when people miss their initial Medicare enrollment deadline.

If you didn’t have Medicare Part A, you might qualify to buy coverage in New York’s insurance marketplace (aka Obamacare) between Nov. 1 and Dec. 31, 2017. But marketplace insurers can’t sell policies to anyone who has any Medicare coverage.

To get Part B coverage before next July, you must either prove that a government official misinformed you about your Medicare enrollment deadline, or your monthly income doesn’t exceed $1,644 and your assets are no more than $11,090 (a couple). That would qualify you for the Medicare Savings Program, which lets you enroll in Part B at any time.

Other readers take note: If you’re 65 years old and covered by an employer with 20 or more employees for whom you or your spouse actively work, your Medicare enrollment deadline is eight months after the job ends or the employer coverage ends, whichever comes first. That’s when that coverage becomes secondary to Medicare. If you miss the deadline, your Medicare premium is permanently higher — and you may face months without primary coverage.

THE BOTTOM LINE Before turning 65, triple-check your Medicare enrollment deadline by asking your employer, your current insurer and Medicare (800-633-4227).

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