Around $32 billion in federal student loans are disbursed to graduate students every year. That’s a drop in the bucket compared to the total amount of outstanding student loan debt – somewhere around $1.3 trillion – but at $32 billion per year and rising, graduate students are increasingly becoming some of the most overburdened student loan borrowers.

A new study by the Center for American Progress found that a group of 20 universities was responsible for one fifth of the total amount of federal graduate student loans disbursed during 2013-2014 academic year. That’s about $6.5 billion, disbursed in one academic year, by only 20 universities. Despite their disproportionate share of graduate student loans (there are a lot of graduate programs at a lot of universities), these 20 schools only educated about 12% of all graduate students. In other words, their share of the student debt load is not at all proportional to the number of students they are educating in their graduate programs. Even more surprising is that the majority of the debt is not attributable to medical or law degree programs (which typically have the highest student loan debt burdens); rather, the majority of the student debt is funding Master’s degree programs.

What is particularly fascinating to me is the diversity of schools represented on this list. Some are prestigious, highly-ranked non-profit universities. Others are massive for-profit degree mills whose presence on this list wouldn’t surprise too many people. There’s even a public state university on the list. It seems that across the board, the “best” and “worst” schools, public and private schools, non-profit and for-profit schools, are all contributing to the massive student loan debt burden that we have in this country.

Here’s the list of the 20 universities, starting with the highest amount of federal graduate student loans disbursed during the 2013-2014 academic year (over $756 million) to the lowest (more than $185 million):

1. Walden University
2. Nova Southeastern University
3. University of Phoenix
4. New York University
5. University of Southern California
6. Capella University
7. Liberty University
8. Midwestern University
9. Grand Canyon University
10. Strayer University
11. Columbia University
12. St. George’s University
13. Kaplan University
14. Ross University
15. Georgetown University
16. DeVry University
17. George Washington University
18. Agrosy University
19. Rutgers University
20. Western University of Health Sciences