• If you're wondering where your stimulus check is, there's good news. You may still be able to claim the money.
• This year's tax filing season offers the opportunity to submit for any missing funds.
• Here's what you need to know about when and how to get any money due to you.

The U.S. government has sent billions of dollars in stimulus checks to Americans since the onset of the COVID-19 pandemic.

Yet some people may still be asking, "Where is my money?"

If you feel that you may have been left in the lurch, there is a way to claim the missing funds.

Submitting a return this tax season can help if you are still owed the recent $1,400 stimulus payment. It can also help resolve the situation if you are missing either or both of the first two checks for up to $1,200 or $600.

The federal tax filing deadline has been extended to May 17 this year.

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If you miss that date, you can still claim any missing stimulus check money by filing for the funds by the Oct. 15 tax filing extension deadline, a spokesman for the IRS confirmed.

However, there are advantages to submitting earlier.

For one, the sooner you put in for any missing stimulus money, the sooner you may receive it. However, it is important to remember that even though you are due a stimulus check, you could owe taxes that are more than that sum.

If you decide to take a tax filing extension, you only have more time to submit your return, not to pay any money you owe. Interest and penalties could accrue on any balance you owe the IRS.

Who could still be eligible for stimulus checks

You're generally eligible for each stimulus check, as long as your adjusted gross income is up to $75,000 if single, $112,500 if you file as head of household or $150,000 if married and filing jointly.

However, each stimulus check comes with its own set of eligibility rules, particularly with regard to phaseouts above those income thresholds and dependent eligibility.

To find out more about why you may or may not qualify for the money, the IRS has information on the first $1,200, second $600 and third $1,400 payments on its website.

As the IRS processes tax returns this season, each week it is deploying additional money in the form of new checks to people it did not previously have on record, as well as "plus-up" payments to those whose previous checks fell short.

You could be eligible for a top-off payment if the return you submit this tax season shows that your income dropped since last year, or you have added another dependent to your family, for example.

If you receive federal benefits and do not typically file a tax return, you may have received your payment automatically. However, the IRS has urged federal beneficiaries to file a return in order to make sure their eligible dependents are included.

On Tuesday, the Social Security Administration announced that any Social Security or Supplemental Security Income beneficiaries who have not received their checks should file tax returns in order to make sure they get their payments.

The government is also encouraging people who it does not have on record to file tax returns in order to get their stimulus checks, particularly the homeless or rural poor.

If you used the IRS online nonfiler tool last year, you generally should not have to resubmit your information through a tax filing. The nonfiler tool has not been reopened this year.

Instead, the IRS is encouraging people to file tax returns, which also helps the tax agency assess whether or not you are eligible for additional tax credits, such as the enhanced child tax credit or earned income tax credit.

How to claim your missing $600 or $1,200 payments

The stimulus checks are generally advance payments of a tax credit.

The 2020 tax returns now offer a section where you can claim the recovery rebate credit for either the first $1,200 stimulus check or the second $600 payment if that money is due to you — line 30 of Forms 1040 or 1040-SR.

On that part of the return, filers can start with the amount of stimulus money they already received and calculate any more funds which they are due. That can be done either through a worksheet provided with the tax form or through tax preparation software.

Once the IRS receives the return, the tax agency will also tally your recovery rebate credit, which means it may correct the amount you claim.

If there is a discrepancy, that could lead to a "slight delay" in processing the return, according to the tax agency.

However, for people who still do not understand why they received less money than they thought they were due, or no money at all, the process could help resolve the confusion.

The IRS will mail letters to filers in this situation to explain what prompted the correction.

Some reasons why the IRS might correct the credit amount include not providing a valid Social Security number or if you were claimed as a dependent on a 2020 tax return. If a dependent was age 17 or over as of Jan. 1, 2020, they will not be eligible for either of the first two checks.

Math errors in the rebate calculations could also prompt a correction.

The IRS offers more information on its website on filing electronically, including free filing and tax preparation services.