Mateo Magdaleno was the first in his family to graduate from high school. For the youngest of 10 children, this was no minor feat. He had moved to Dallas from Mexico City as a toddler. His father died shortly after. By 8 years old, he had seen both his brothers spend time in prison and six of his sisters drop out of school.

Galvanized by his family’s struggles, Mateo continued to pursue his education beyond high school. He enrolled in Mountain View College, a community college in Dallas, where he juggled studying and working full-time. He graduated with the institution’s highest distinction and — after earning a Cooke Scholarship — transferred to Southern Methodist University.

Though living in a homeless shelter and struggling to find food for much of his time at SMU, Mateo completed his bachelor’s degree and served as special assistant to a dean. After graduating, he earned the U.S. Congressional Award Gold Medal, a civilian honor for youth given by Congress. He has since founded a nonprofit organization, and he dedicates his time to supporting organizations committed to increasing graduation and college enrollment rates among urban students.

Mateo’s successes are the result of years of hard work and personal sacrifice. But his educational transformation was made possible through an aid program that helps more than 7 million students a year who need financial assistance to afford college: Pell Grants.

For decades, Pell Grants have served as a lifeline to opportunity and economic mobility for Americans seeking to earn a college education. Two-thirds of African American students and half of Latino students are Pell recipients. With the Trump administration taking aim at affirmative action, it is vital we ensure the barriers to a college education remain as low as possible for students from low-income families. But as college costs continue to rise, Pell’s lifeline is now in danger.

A college education is fast becoming a prerequisite for success in today’s competitive labor market. A new report from Georgetown University reveals that people with degrees from four-year institutions held 55 percent of the nation’s well-paying jobs in 2015, compared to 40 percent two decades ago. Yet too many low-income students remain shut out of higher education and elite colleges. A study last year by the Jack Kent Cooke Foundation found that only 3 percent of students at top colleges come from the poorest 25 percent of families, while nearly three-quarters come from the wealthiest 25 percent.

Research from the Education Trust and the Department of Education under the Obama administration reveals that many colleges and universities across the country are successfully supporting strong outcomes for Pell-eligible students. The Education Trust’s College Results Online shows that City University of New York-Queens, University of California at Riverside, Temple University, the University of South Florida, and John Carroll University all boast graduation rates for Pell students that are at least 10 percentage points higher than peer institutions serving similar students, and the graduation rate gap between Pell and non-Pell students at these schools is less than 3 points.

But the buying power of Pell Grants is decreasing, and with it, the program’s ability to aid students who can benefit most from the opportunities that a college education can make possible. In 1980, a Pell Grant covered 77 percent of the cost of attendance at a public university. Today, it covers just over 29 percent.

Importantly, since 2013, Pell Grants have been indexed to inflation to better ensure that our federal investments in postsecondary education keep pace with the rising costs of college. That critical provision will expire at the end of this school year, however. If Congress fails to adjust Pell for inflation, the award will cover just one-fifth of college costs in 10 years.

Diluting the power of Pell will exacerbate significant financial barriers that low-income students face. These students are required to finance the equivalent of three-quarters of their family income to cover college costs. And these students are disproportionately reliant on private loans.

Failing to protect the nation‘s investment in Pell Grants could help to fuel a student loan disaster that will rival the 1980s savings and loan crisis in scale.

What’s worse: short-changing a generation of low-income students will deprive them of achieving their full potential and our nation of the value that these students stand to add to our economy and our society.

Students like Mateo—young people with great promise but who face difficult circumstances and seemingly insurmountable financial barriers to college—can achieve incredible things when we invest in them. We believe that in America, talent is ubiquitous, but the unfortunate reality is that opportunity is not. We know that Mateo and students like him have what it takes to thrive, but they can’t demonstrate just how incredible they can be if they can’t afford to step foot on a college campus.

Earlier this year, congressional leaders came together with bipartisan support to ensure Pell Grants were available year-round for students. When it comes to maintaining the indexation of Pell to inflation, we urge them to show the same commitment to our students’ success.

Harold O. Levy is executive director of the Jack Kent Cooke Foundation. John B. King Jr., who served as education secretary under President Barack Obama, is president and chief executive of the Education Trust.