When it comes to who gets into and graduates from college, you probably shouldn’t outright disregard grades and SAT scores—but a student’s financial situation can be a troublingly valuable indicator of their chances.

While more than 80 percent of high-income students enrolled in college in 2012, only about half of low-income students did the same, according to the National Center for Education Statistics. And among those that did make it on campus, more than half of the wealthier students graduated, dwarfing the nine percent of low-income ones who managed to do the same, economists Martha Bailey and Susan Dynarski of the University of Michigan found.

So what exactly is it that leads to this so-called “achievement gap”?

It’s a quagmire of economics and politics, but through it all there’s an uncontroversial common thread, outlined by the White House in a report issued earlier this year: “Low-income students often lack the guidance and support they need to prepare for college, apply to the best-fit schools, apply for financial aid, enroll and persist in their studies, and ultimately graduate.”

In plain words, poor kids have less support and fewer resources to get into the right schools and succeed once they’re there. But around the country, there are efforts being made to help these students find that support in unconventional, but surprisingly common sense, places.

One of those efforts, the Posse Foundation, has been tackling the problem since 1989. At the time, Deborah Bial, the organization’s founder, was working at a youth leadership development after-school program in New York City. There, she ran into a student who’d dropped out of college and told her, “I never would have dropped out if I had my posse with me.”

“It made so much sense,” Bial said. “Why not send a posse or a team or a group of kids together to college so they could back each other up? That way, if you grew up in Chicago or in the Bronx but you ended up in Middlebury, Vermont, or Ithaca, New York, you'd be a little less likely to turn around and come home.”

The Posse Foundation identifies talented students, places them in a posse with nine other scholars from their hometown, finds schools that will give them full four-year scholarships, and then provides them with mentoring as they work toward their degrees.

Twenty-five years later, the organization has sent more than 5,500 mostly low-income students to college to 51 different schools around the country. Since its humble beginnings in New York City, the program now works with high school students in Atlanta, Boston, Chicago, Los Angeles, Miami, New Orleans, Washington, D.C., and most recently, Houston.

That almost obvious kind of support—people from the same place you’re from, going to the same place you’re going—has helped the program’s students achieve a 90 percent graduation rate, which is significantly higher than the national rate of 59 percent.

“The whole idea of Posse getting folks access to colleges and universities who would not have been selected through the normal college selection process is really a fascinating one,” said Julie Parsons, a senior vice president at Allstate and a member of the Posse Foundation Chicago Chapter’s Advisory Board. “And it’s very compelling given their success rate.”

Based on the results, it puts college to work the way college is supposed to work. After graduating, Posse’s alumni have gone on to become deans at colleges, partners at law firms, school principals and teachers, restaurant owners, artists, executives at banks and financial companies, nonprofit founders, and much more.

And these examples are not the exception, Bial said. They’re the rule.

“If you think about all those people out in the workforce in various leadership roles and the positive impact that they can have, it’s sort of a ripple effect through society,” said Parsons.

One alumnus, Leroy Foster, a member of Vanderbilt University’s Posse 7 from 1996, has gone full circle in his experience with the foundation, recently becoming the head of an upcoming chapter that will be based in the San Francisco Bay area.

“I'm someone that's a true believer because I know what this program's done for me,” Foster said. “Just knowing that we're going to create opportunities for so many people that right now aren't getting them—that's something that's really exciting to me.”

But both he and Bial know the problem is bigger than what a single organization can solve. Every year they have to turn away thousands of talented teenagers—let alone the millions that don’t take part in the Posse application process. Which is why she intends to keep growing the Posse Foundation, opening doors for more students and creating leaders who will drive positive change in the future.

“These are really smart kids who could compete if you just gave them a chance,” she said. "What we hope is that many more top colleges and universities will say ‘We want to try this. We want to join the movement—the Posse movement.’”