DALLAS (CBSDFW.COM) – More than 9,000,000 Americans have still not received a federal stimulus payment more than five months after the IRS began sending out the $1,200 payments.

The IRS is sending letters this month to millions of Americans, including nearly 800,000 in Texas, encouraging them to see if they’re eligible to claim a stimulus payment by submitting their information using the Non-Filers portal tool at irs.gov.

October 15 is the deadline for people who have not received a stimulus payment to apply through the Non-Filer portal on the IRS website.

September 30 is the deadline for people who have already received stimulus payments but did not get the extra $500 for qualifying children.

This typically applies for those who receive Social Security, SSI or VA benefits. They too are encouraged to use the Non-filer portal on the IRS website to provide information about their children.

Robert Probasco, the tax director at Texas A&M University School of Law, said as soon as the CARES Act was passed the IRS was under so much pressure from Congress and the public to get the stimulus payments out that millions of Americans were left out.

“The IRS really wasn’t prepared going into this to get these payments out especially to those who typically don’t have to file taxes,” Probasco said.

The IRS has changed its deadlines and guidelines multiple times which had added to confusion and frustration for Americans waiting on their stimulus checks.

However, Probasco said he believes the October 15 will be the final deadline.

Those who do not meet this deadline and qualify for a stimulus payment will have to wait and claim the credit on their 2020 federal tax return in 2021, according to the IRS.

If you are required to file a tax return for 2019, experts say do that before using the Non-Filer portal to enter your information for the stimulus check. Otherwise, you may not be able to file your taxes electronically after using the Non-filer tool.

The United Way has set up a helpline (844-322-3639) for people to call for questions about or help with getting a stimulus payment. You can find more information here.