If you're like many Americans, you may be baffled as to whether or not your spouse is eligible for Medicare coverage based on your work record.
In fact, when some pre-retirees were recently quizzed on Medicare, most didn't know for sure.
The test — posed by MassMutual to 500 Americans ages 60 to 64 — found that most were wrong about their spouse's eligibility for coverage.
The true or false question said, "If I am not eligible for Medicare, but my spouse is eligible, I can receive Medicare benefits."
Just 21 percent of respondents accurately answered correctly with "True," while 79 percent answered incorrectly with "False."
The key number to keep in mind about whether or not your spouse qualifies for coverage under your record is whether or not they have turned 65. To get Medicare coverage, a person has to either be 65 years old or medically disabled.
"A lot of people don't know that a spouse can be covered for Medicare under their spouse's work record," said Medicare expert Katy Votava, president of Goodcare.com, an independent consulting firm that specializes in health care.
To qualify for Medicare, you need to have paid into the Social Security system. Just like with Social Security benefits, you can qualify for Medicare coverage under your spouse's record.
That continues if you divorce, provided you meet certain conditions outlined by the Social Security Administration.
One of the challenges for spouses can be finding coverage until they reach the age at which they are eligible for Medicare, according to Votava.
If you are 63, for example, and expect to get Medicare coverage under your spouse's record, you will have to wait for two years.
And if you are not able to get health coverage through your own job, that could be an expensive endeavor.
"That can be somewhat challenging," Votava said. "They have to get their own, and it can often be more costly than if they had access to insurance through a corporation."
If your spouse is younger, they must be at least 62 years old — the age at which they can qualify for Social Security retirement benefits — in order for you to get Medicare coverage on their record, according to Diane J. Omdahl, co-founder and president of 65 Incorporated, a provider of Medicare education.
In addition, there is the risk that if you are covered by your spouse's employer health plan and turn 65 that you can be kicked off the plan.
This is not common, Votava said, and would only happen if the employer has fewer than 20 employees. For companies with 20 employees or more, there are rules that prevent them from excluding someone who is Medicare eligible from coverage.
If you do stay on employer coverage through a small company, Medicare will often pay first before other health insurance coverage kicks in.
"A lot of people don't realize that their employer coverage – once they're 65 and in a smaller firm, 19 or fewer – doesn't cover as much as they think it covers," Votava said.
If you are in this situation, watch out that you do not get tripped up by these rules, Omdahl said.
Even if an employer with less than 20 employees allows you to stay on the plan, there are times when Medicare will be the primary payer. If you do not sign up for Medicare Parts A and B, that could become a problem, Omdahl said.
"Because there's no primary payer, the group plan won't pay, because it's a secondary payer," Omdahl said.
You would be able to sign up for Medicare right away, but your back medical expenses would not be covered, Omdahl said.
You should also be mindful of how your ability to save through a health savings account changes if you or your spouse get Medicare coverage.
A health savings account lets you put away pre-tax money toward health care expenses alongside coverage by a high deductible health plan. But if you are covered by Medicare, you are no longer able to contribute to one of these accounts.
If you have an HSA through your employer and your spouse enrolls in Medicare, you can still continue to make new contributions to that account, Omdahl said.
More from Personal Finance: