Haydee Cruz owes more than $200,000 in student loans Source: Haydee Cruz

After Haydee Cruz and her daughter toured Full Sail University in Winter Park, Florida, the two were hooked. Then came the math. To finance four years of tuition and living expenses at the for-profit college, both Cruz and her daughter would have to go into debt. Cruz alone borrowed around $160,000 in "parent PLUS" loans from the government. Repaying that balance has been a challenge for the 63-year-old social worker.

She makes around $50,000 a year and the monthly student loan bill is more than $600. Since her payments barely cover the interest on the debt, the amount she owes has ballooned to well over $200,000 today, she said. At this rate, when she's 85, she'll be done with the payments. In the meantime, she's barely able to save for her retirement. "I have nothing that is going to sustain me if I stop working," Cruz said. "This loan governs my life." As college costs rise, more students are hitting the federal student loan limits with a portion of their bill unpaid. Increasingly, their parents are borrowing to make up the difference.

Source: Mark Kantrowitz Today, at least 3.4 million people hold so-called parent PLUS loans and they owe nearly $90 billion, according to a new report by the Brookings Institution, a public policy research group. (Those numbers don't capture parents who have consolidated their debt, in which a loan is rolled into a new one.) Parent borrowers took out $16,100 on average in 2014, up from an inflation-adjusted $5,200 in 1990. For comparison, the average undergraduate student borrowed about $7,300 in 2014. Currently, the average parent PLUS balance is $25,600. Some parents take out loans for multiple children, the researchers note, increasing their debt even more. Nearly 9 percent of parents who began repayment in 2014 owed more than $100,000.