Only 47% of Americans correctly answered TIAA Institute questions on spending, borrowing, investing and retirement, the lowest score the institute has recorded.
TIAA's findings point to broad weakness in basic money knowledge, with economist Vance Ginn linking the slide to inadequate early financial education and limited instruction on taxes, credit and investing.
Low financial literacy carries immediate household consequences: studies cited in the report say affected adults are four times more likely to struggle to make ends meet and four times more likely to lack emergency savings.
The report adds to concerns that weak financial skills could worsen future debt and budgeting problems unless financial education improves earlier in school.