While the study classified even baby boomers as “older Americans,” its most dire findings were for the oldest group. Among people over 75, the foreclosure rate grew more than eightfold from 2007 to 2011, to 3 percent of that group of homeowners, the report found.

“Despite the perception that older Americans are more housing secure than younger people, millions of older Americans are carrying more mortgage debt than ever before, and more than three million are at risk of losing their homes,” the report found. “As the mortgage crisis continues, millions of older Americans are struggling to maintain their financial security.”

The report was based on nationwide loan data that covered a five-year span. The profile of those facing foreclosure has changed since 2007. As the average age and wealth of those people rise, their foreclosures are less likely to involve high-interest loans. In fact, most foreclosures are now the result of prime loans rather than subprime ones, according to the Federal Reserve Bank of New York.

Instead, older Americans are losing their homes because of pension cuts, rising medical costs, shrinking stock portfolios and falling property values, according to Debra Whitman, AARP’s executive vice president for policy. They are also not saving enough money. Half of households whose head is between 65 and 74 have no money in retirement accounts, according to the Federal Reserve.

At CredAbility, an Atlanta-based credit counseling agency, the average age of callers needing help has risen to 49 from 43 in recent years. Scott Scredon, a spokesman for the agency, said most older Americans facing foreclosure are frugal but are unable to live on fixed incomes with the rising cost of living.