High school students know very little about how financial aid works, according to a new analysis.

An overwhelming majority  of 11th and 12th graders (from 73% to 81%, depending on income group) were unaware that the government will pay their interest on existing loans while they are still in college, according to a new analysis of data by the ACT’s Center for Equity in Learning. From 67% to 70% didn’t know about a program that allows students to repay loans slower, based on how much money they make after college, the study found. Data were collected in April 2018 from approximately 1,200 students registered to take the ACT.

College debt can have lifelong financial effects, and students across all income levels said tuition was a “very important” factor in choosing a college. Of those surveyed, 27% of black students and 31% of those who are first in their family to go to college anticipate paying tuition without family help, compared to 20% overall.

“The findings highlight an urgent need for more financial literacy–specific interventions, especially in light of the economic stakes at hand,” said Jim Larimore, chief officer at the ACT’s Center for Equity in Learning. The center outlines steps for improvement, including tailoring information for different student groups and improved outreach by college representatives.

U.S. student loan debt now tops $1.5 trillion, an amount that has doubled in less than a decade. The average borrower has racked up nearly $40,000 in student loan debt, outpacing credit-card debt. Student loan debt trails home mortgage loans as the greatest source of personal debt, according to the study.

This article was provided by Bloomberg News.