The number of older Americans taking on student debt on behalf of their children and grandchildren has quadrupled in the past decade, with consumers over 60 now holding $66.7 billion in student loan debt, according to a new report by the Consumer Financial Protection Bureau.

A recent story in the Washington Post said that the skyrocketing cost of college has placed a particular burden on older Americans, many of whom are struggling to pay back growing debts in their retirement years, according to the report. Nearly 40 percent of federal student loan borrowers over age 65 are in default, the highest rate for any age group, the data show.

“Student loan debt is clearly an intergenerational problem, and what we’re seeing is that this is unfortunately putting older consumers’ retirement at risk,” said Seth Frotman, assistant director of the Office for Students at the CFPB. “Older Americans are struggling under the weight of student loan debt.”

Americans owe nearly $1.4 trillion in outstanding student loans. A slow job market recovery, growing income inequality and stagnant wages have made it difficult for younger Americans to be economically independent, and now there are signs that those financial struggles are dragging down their parents and grandparents as well.

“A large portion of older student loan borrowers struggle to afford basic needs,” the report said, adding that older borrowers were increasingly likely to have skipped necessary doctors’ appointments and prescription medications because they couldn’t afford them.

A growing number of borrowers over age 65 also said their Social Security benefits — often the only source of regular retirement income for older Americans — had been seized because of unpaid student loans, according to the report. Those with student loan debt also had less money saved for retirement than their counterparts without student debt did.