The American Rescue Plan, passed by Congress in March, has mandated stimulus checks of $1,400 to most Americans. But some Americans have fallen through the cracks- including at least 2 million citizens in California, according to a recent study.

California Policy Lab released a study in early April called The Stimulus Gap, estimating that as of the start of the month, about 2.2 million eligible Californians were “likely did not receive these or prior stimulus payments automatically and may be in danger of not receiving them at all.” The total amount of money in those checks is $5.7 billion.

Those missing the payment have been advised to file a tax return to get their money.

The authors of the study recommend that the IRS bring back the online Non-Filers Tool, which has been dormant since last November. The tool would also allow taxpayers to use it to claim their Earned Income Tax Credit and Child Tax Credit.

“The IRS was able to get payments out fast to most safety-net enrollees in California — but in its speed, we estimate that 25% of California’s safety-net enrollees did not automatically receive all payments for which they were eligible. Across all three rounds of the stimulus, roughly 6.6 million Californians enrolled in safety-net programs automatically received (or will soon receive) an estimated $18 billion in automatic stimulus,” the report stated.

“However, we estimate that 25% of safety-net enrollees, some 2.2 million Californians, are caught in the Stimulus Gap and may miss out on approximately $5.7 billion in stimulus payments.”

CalMatters, earlier this week, reported that a group of  United Way staffers had visited a small town near California’s border with Oregon, which is the area of the state with the largest concentration of Californians who are missing their stimulus check. The staffers have been helping residents fill out their tax returns, in order to help them receive their stimulus payments.

“Anything that has to do with taxes or government is something they would prefer not to deal with,” Theresa McCausland of the United Way said of the people in question, “even if it means a few hundred or thousand dollars in their pocket.”

California, meanwhile, is a rare state that is offering their own stimulus check. The Golden State Stimulus, signed into law in February by Gov. Gavin Newsom, confers a one-time payment of $600 or $1,200 to eligible recipients, in order to “support low-income Californians” and “help those facing a hardship due to COVID-19.”

Meanwhile, some state and local governments are still awaiting instructions on how exactly to spend stimulus money that’s been allocated to them.

Stephen Silver, a technology writer for The National Interest, is a journalist, essayist and film critic, who is also a contributor to The Philadelphia Inquirer, Philly Voice, Philadelphia Weekly, the Jewish Telegraphic Agency, Living Life Fearless, Backstage magazine, Broad Street Review and Splice Today. The co-founder of the Philadelphia Film Critics Circle, Stephen lives in suburban Philadelphia with his wife and two sons. Follow him on Twitter at @StephenSilver.