Getting an advanced degree doesn’t come cheap, which is why graduate students carry nearly half of all student debt. But it turns out that a handful of schools are responsible for a large share of that money.

A new study from the Center for American Progress (CAP) found that 20 universities received one-fifth, or $6.5 billion, of the total amount of loans the government gave graduate students in the 2013-2014 academic year. Those schools, however, only educate 12 percent of all graduate students.

What’s striking about the Center’s findings is that a majority of the debt taken to attend the 20 schools on its list is not for law or medical degrees that promise hefty paydays. Most graduate students at those schools are seeking master’s degrees in journalism, fine arts or government, according to CAP.

Still, at two foreign medical schools, St. George’s University in Grenada and Ross University in Dominica, students borrowed more than $200 million in a single school year. Medical schools in the Caribbean are often a refuge for students rejected from top American schools, but their tuition easily rival schools in the United States. Tuition for one semester at Ross, for instance, costs up to $21,710.

It’s not exactly shocking that pricey private schools like New York University, Georgetown University and George Washington University made the list–tuition alone at all three schools is well over $40,000 a year. But the eight for-profit colleges, including University of Phoenix and Capella University, may raise some eyebrows.

Indeed, students borrowed the most amount of money, $756 million, to attend Walden University, a for-profit school that specializes in offering graduate degrees in education, healthcare and business. The second highest loan balance on the list is attributed to Nova Southeastern University, a private college in Florida where 59 percent of students are working toward graduate degrees online.

Although online programs are billed as time and cost effective, schools like Nova and Liberty University prove otherwise. About 98 percent of graduate students at Liberty, founded by evangelical leader Jerry Falwell, are enrolled in online programs that led them to borrow $351 million in a single year.

The government lets graduate students borrow far more than undergrads. Students pursuing a bachelor’s degree can take out no more than about $27,000 from the government, unless they’re married, over age 24 or otherwise independent from their parents. On the other hand, graduate students can borrow the full cost of attendance and wind up with six-figure debt by the time they earn a degree.

“Policymakers should consider how much graduate lending is sustainable, and examine the value of graduate credentials,” said Elizabeth Baylor, director of postsecondary education at the Center for American Progress. “Degrees in medicine at traditional medical schools offer a clear path to a career with very positive economic outcomes. It’s an expensive education to deliver and the cost students bear makes some sense. However, an online master’s degree, which is cheap to deliver—from an institution with uncertain career outcomes—may not merit unlimited graduate loans.”

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