The initial wave of second stimulus checks is going out this week, with the IRS and Treasury working fast to send tens of millions of economic impact payments to Americans before Jan. 15. Why? That’s the cutoff stated in December’s stimulus bill. After that time, new stimulus checks for up to $600 per person — sorry, the $2,000 stimulus checks are a non-starter — won’t be able to go out to people through direct deposit or the mail. (Here’s how to track your second stimulus check.)

So what happens if you’re one of the many people who the IRS can’t get to in roughly two weeks from now until then? Your second stimulus check won’t be forfeit, don’t worry, but you will have to do a little extra legwork — and perhaps dig into a deeper well of patience — to wait out your check.

What happens is that when you file your taxes this year (or at least during tax time), you can claim your second stimulus check money — or even a catch-up payment from the first check — in the form of a Recovery Rebate Credit from the IRS. This credit would either increase the amount of your tax refund or lower the amount of the tax you need to pay by the amount of stimulus money the government owes you on the first and second payments. We break down what you need to know. This story was updated recently with new information.

When and how you’ll file a claim for a missing stimulus check this year

If you belong to one of the groups outlined below, or estimated your total for the first stimulus payment or used our calculator to get an idea of your payment for the second and think the IRS didn’t send the full amount you qualified for, you have another chance this year to claim missing stimulus check money through an IRS Recovery Rebate Credit.

You can file for this credit when you do your federal tax returns this year; if the typical schedule holds, your federal tax return will be due April 15 (though in 2020, the IRS extended the deadline to July 15 as a result of the COVID-19 pandemic).

While the IRS doesn’t have final instructions yet for every personal situation (more on these below), the agency does say that people who file taxes can use what will be called the Recovery Rebate Credit on the 2020 Form 1040 or Form 1040-SR to claim a catch-up payment. The IRS will provide a Recovery Rebate Credit Worksheet to help you work out if you are missing a payment and for how much.

To start, you’ll need the IRS’ calculated amount from the letter called Notice 1444 for the first payment and Notice 1444-B for the second payment when you file this year.

If you file for the credit and are owed money, you’ll either see the amount of your tax refund increased or the amount of tax you owe lowered, depending on the amount of stimulus money you’re eligible to receive.

If you don’t normally file a federal tax return, here’s what you’ll do

Last fall, the IRS sent letters to 9 million Americans who may have qualified for a payment but perhaps didn’t know they needed to register to claim it. This group — which the IRS categorizes as “nonfilers” — includes people who didn’t file a tax return in 2018 or 2019, such as older adults, retirees, SSDI or SSI recipients and individuals with incomes less than $12,200. Those in this group needed to file a claim using the Non-Filers tool by Nov. 21. The IRS said if you missed the deadline you can claim the payment, which, again, it calls a Recovery Rebate Credit, this year when you file a 2020 federal income tax return:

When you file a 2020 Form 1040 or 1040SR you may be eligible for the Recovery Rebate Credit. Save your IRS letter – Notice 1444 Your Economic Impact Payment – with your 2020 tax records. You’ll need the amount of the payment in the letter when you file in 2021.

If you’re missing a payment for a dependent child, know this

Under the CARES Act, each qualifying child dependent — those 16 years old and younger — was eligible for a $500 check. But some people’s payments were short $500 for each eligible dependent.

If you claimed it by Nov. 21 of 2020 you should receive the payment in December of last year. You can use our stimulus check calculator to get an idea of how much you may be owed.

As with the nonfilers, if you missed the deadline, the IRS said you can claim the payment on your 2020 federal tax return this year, by filing a 2020 Form 1040 or 1040-SR.

Note that in a few cases, where parents are separated or divorced and share joint custody of a dependent, each parent can get a $500 payment per eligible child, so you may not even be aware you’re eligible for the payment to begin with.

Was you stimulus check garnished by mistake?

Although there are a few cases where the federal government or a debt collector could seize your first payment to cover an outstanding debt, in general, if you qualify for a check, it’s yours to spend or save as you want. One area where the federal government can garnish the first check is for overdue child support. You can can’t have your second check seized for overdue support. However, if the parents are separated or divorced, only the spouse who owes child support should have the check seized.

According to the IRS, the parent who does not owe child support should receive their portion of the first payment without having to take action. If you haven’t received your check, the IRS said it is working to send out the missing payments. While you don’t have much recourse to appeal IRS decisions, you can also try the Non-Filers tool to create a record of your claim.

If you used our stimulus check calculator and believe your check amount isn’t accurate

Finally, if you use our first stimulus check calculator or second payment calculator and find you may have qualified for a larger payment than you received, you can use the IRS Get My Payment tool to see if a check is in the works. If the IRS is waiting on information from you it needs to make your payment, you might still be able to claim your money this year.

If you’re a US citizen abroad, in US territories or are not a citizen

The IRS has rules that set the payment eligibility guidelines for US citizens who live abroad and non-US citizens who work in the US — along with spouses of nonresident aliens. We have a guide that walks through the various eligibility scenarios along with what to do if you qualify but didn’t get a check.

People in jail or prison qualify for a check by court order

Since April, when it first started sending payments, the IRS has gone back and forth on whether those who are in US jails and prisons qualify for a stimulus check.

A ruling last fall from a federal judge in California, however, seemed to have settled the question for now and required the IRS to contact those incarcerated who can file a claim for a stimulus check. The deadline to file a claim in 2020 — either through the mail or online — has passed. As with others who are missing a payment, the IRS said if you do not receive a payment by Dec. 31, 2020, you may be able to claim it this year by filing a 2020 Form 1040 or 1040-SR.

For everything to know about the first payment, see our guide to the first round of checks. We also have an idea of how quickly the IRS could send out the second stimulus check, what priority group you would be in to receive a second check, and what other benefits you might expect in another economic relief package.