Most Americans nearing retirement expect Social Security to be their biggest source of income.

Yet many of those people, ranging in age from 55 to 65, are unaware of the basics about the program, according to new research from MassMutual.

About 43% of the 1,500 people surveyed do not know how much of their income will come from Social Security benefits.

The results to that answer were “stunning” for a cohort so close to their retirement years, said David Freitag, a financial planning consultant and Social Security expert at MassMutual.

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In addition, the firm posed a 13-question true/false quiz to the respondents. The result: 69% either barely passed or failed. More than one-third — 35% — of respondents failed. Meanwhile, more than one third — 34% — just passed with a grade of D.

Most respondents, 84%, know their benefits will be reduced if they claim benefits early.

But about half of respondents still do not know how long it pays to wait to claim.

“There’s no tangible reason why anybody would ever wait past age 70,” Freitag said.

To see how well you would do on the quiz, decide whether the statements below are true or false, and compare your answers to the key below.

True or False:

1. In most cases, if I take benefits before my full retirement age, they will be reduced for early filing.
2. If I am receiving benefits before my full retirement age and continue to work, my benefits might be reduced based on how much I make.
3. If I have a spouse, he or she can receive benefits from my record even if he or she has no individual earnings history.
4. Generally, if I am in a same-sex marriage, there are different eligibility requirements when it comes to Social Security retirement benefits.
5. If I have a spouse and he or she passes away, I will receive both my full benefit and my deceased spouse’s full benefit.
6. The money that comes out of my paycheck for Social Security goes into a specific account for me and remains there, earning interest, until I begin to receive Social Security benefits.
7. If I file for retirement benefits and have dependent children aged 18 or younger, they also may qualify for Social Security benefits.
8. If I get divorced, I might be able to collect Social Security benefits based on my ex-spouse’s Social Security earnings history.
9. Under current law, Social Security benefits could be reduced by 20% or more for everyone by 2035.
10. Under current Social Security law, full retirement age is 65 no matter when you were born.
11. If I delay taking Social Security benefits past the age of 70, I will continue to get delayed retirement credit increases each year I wait.
12. Social Security retirement benefits are subject to income tax just like withdrawals from a traditional IRA account.
13. I must be a U.S. citizen to collect Social Security retirement benefits.

Answers:

1. True (84% answered correctly)
2. True (77%)
3. True (72%)
4. False (69%)
5. False (65%)
6. False (60%)
7. True (56%)
8. True (56%)
9. True (55%)
10. False (53%)
11. False (49%)
12. False (38%)
13. False (29%)