High school graduates are passing up billions of dollars in free money to help them pay for college, a new analysis suggests.

By not filling out or completing the free application for federal student aid, or FAFSA, high school graduates lost out on as much as $2.7 billion in financial aid they wouldn’t have to pay back in the last academic year, according to a study published Wednesday by NerdWallet, a personal finance site. Researchers at the site came to that conclusion by estimating the number of high-school students who didn’t file the FAFSA who would also be eligible for Pell Grants, the free money the federal government gives to low- and moderate-income students.

“The FAFSA is really the gateway to getting federal aid,” said Nonso Maduka, a financial-aid expert at NerdWallet. So even if a student is eligible for a Pell Grant, she won’t get it unless she fills out the form. That also applies to federal student loans and in many cases different types of college or state-specific grants or loans.

The NerdWallet study indicates that more than 1 million students either aren’t filling out the FAFSA at all or are starting and not completing the form. The analysis does cover high school graduates who may be Pell eligible but who may not go to college, so it likely overestimates the total amount of money students are giving up. Still, there are a variety of reasons why a prospective college student may not fill out the form and pass up their chance at aid — they may think they’re ineligible or get scared off by the length of the application and the information required, said Maduka.

Politicians on both sides of the aisle, including Democratic front-runner for president Hillary Clinton and Lamar Alexander, the Republican senator from Tennessee who chairs the Senate committee on health, education, labor and pensions, have pushed for FAFSA reform that would make the application simpler to fill out in the hopes that families get more of the aid to which they’re entitled.

The Obama administration has already taken steps to make it easier to fill out the form. Starting in the 2017-2018 academic year families can base their application on tax information from two tax years prior to the year they’re applying in. That will make it more likely that families will have accurate tax information on hand when they fill out the form because they won’t be relying on tax forms they have not yet filed for the FAFSA.

In addition, families will be able to start filling out the application in October instead of having to wait until January, so they’ll get a sense of their financial aid eligibility before applying to schools.

But trying to address the issue of college affordability by simply cutting the length of the FAFSA misses the point, said Sara Goldrick-Rab, a professor of educational policy studies at the University of Wisconsin. That’s because financial aid, particularly the kind you don’t have to pay back, is often a zero-sum game—an uptick in the number of students who apply for aid could mean that students actually get less money in the long run.

“We can’t pretend like we’re providing enough resources in the system such that if our FAFSA rates go up everybody’s money goes up,” she said.

What do technology late adopters know that we don't?

Instead of devising a system that focuses on who is deserving of aid, Goldrick-Rab said policy makers should be working to make college free for everyone. That would ensure that students who aren’t filling out the FAFSA for a variety of reasons — they think they won’t get aid, they’re undocumented immigrants, they simply don’t have enough or the right information — can still afford to go to college.

“I would say the answer is not fix FAFSA — it’s kill FAFSA,” she said. “The evidence that students continue to not fill out the FAFSA and leave “money on the table” is evidence that we’re not going to tweak our way out of this.”

But as long as the FAFSA remains the key to getting federal financial aid, Maduka has a few tips for students and their parents:

Fill it out: “Don’t be afraid of it, don’t be daunted by the form, remember the first letter stands for free,” he says.

Prepare: Get your tax and other documents in order so that you have all the information readily available when you’re applying.

Avoid Scams: Companies will often offer to help you fill out the FAFSA for a fee. Remember it’s a free form so businesses trying to get you to fork over money to fill it out may be scams.

Check Your Work: Once families submit a FAFSA the information is often verified by financial aid officers that means if data proves to be incorrect you may not get the aid to which you’re entitled.