Millennials have tons of debt. But it’s not necessarily from being irresponsible. A new study from LendingTree shows that the greatest amount of millennial debt stems from getting an education.

LendingTree analyzes credit report data from millennials in the 50 biggest metro areas in the U.S. and found that student loan debt outweighs all other types of debt (excluding mortgages), clocking in at 40 percent of their total credit and loan balances.