WASHINGTON (AP) — Potentially tens of thousands of students awarded a Pell Grant or other need-based federal aid for the coming school year could find it taken away because of a mistake in filling out the form.

The mistake primarily stems from an online form change to the Free Application for Federal Student Aid, or FAFSA, made Jan. 1 that expanded the field to enter income.

Many applicants unnecessarily entered a decimal point and cents that the system ignored. The error led to students being declared eligible for aid when they are not — and ineligible when they are.

Fewer than 200,000 applicants have been declared eligible when they are not, the Education Department said. Data checks to try to identify those students are underway, the department said, and the form has been changed to help prevent the mistake in the future.

“Although some applicants and many institutions have already identified and corrected the error, not all necessary corrections have been made,” the department said in an online posting.

The FAFSA form is filled out annually by millions of applicants. Unlike student loans, Pell grants are not repaid.

“Students who have questions should definitely look at their financial aid report or check in with their financial aid office if they think there may have been an error,” said Justin Draeger, president of the National Association of Student Financial Aid Administrators.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.