Two in five near-retirees say Social Security will be their largest anticipated source of income, but many of them are clueless about basic facts, such as the full retirement age to collect benefits, according to MassMutual.

MassMutual said 41% flunked a quiz it gave pre-retirees about Social Security, and 37% got a D. Fewer than 1% received an A+ by answering all 13 true/false statements correctly.

The online quiz, commissioned by MassMutual and conducted by PSB Research in January, queried 1,500 Americans aged 55 to 65 who have not filed for Social Security retirement benefits. 

Forty-five percent of respondents were unaware of the full retirement age, and 52% did not know that the ability to receive delayed retirement credit ends at age 70. But 92% knew that collecting before full retirement reduces benefits. Also, 84% knew there are consequences to receiving benefits before full retirement age and continuing to work, and that their benefits may be reduced based on their earnings.

Seventy-seven percent did not know that you do not have to be a U.S. citizen to collect retirement benefits, MassMutual said

MassMutual noted that more near-retirees this year were knowledgeable about benefits relating to their spouse, divorce and death. Seventy-five percent knew that spouses with no earnings history could receive benefits through their spouse, and 70% were aware that a surviving spouse does not receive both their full benefit and their spouse’s full benefit in the event of their spouse’s death. Furthermore, 59% knew that if they got divorced, they might be able to collect Social Security benefits based on their ex-spouse’s earnings history.

“We have been conducting this quiz with near-retirees for the last 10 years and with new cohorts nearing retirement each and every year, we see similar patterns of confusion when it comes to Social Security retirement benefits,” Paul LaPiana, head of brand, product and affiliated distribution with MassMutual, said in a statement. “What’s more, we are finding that people at this stage of their lives should have some basic estate planning documents in place, and a staggering number do not.”

LaPiana added said "these individuals have not yet filed for Social Security benefits so they have time to understand the basic facts that can either help or hurt their financial situations in retirement.”