While many Americans have received their $1,200 stimulus check—more than 152 million by last Friday, according to the Internal Revenue Service (IRS)—many others are still wondering why their economic relief has not yet arrived.

For some, the reason may be because they do not qualify for a stimulus check, which the IRS officially calls an Economic Impact Payment. Americans with a “single” filing tax status whose adjusted gross income is more than $99,000 annually do not qualify, nor do married couples who file jointly and make more than $198,000. Tax filers who serve as the heads of their households and make more than $136,500 also do not qualify, according to the IRS website. Dependents—those who live in the U.S. as nonresidents and those without Social Security numbers—also do not qualify for a stimulus payment.

These are other reasons why the payments may have also been delayed.

The IRS Hasn’t Gotten to You Yet

According to a memo circulated by congressional legislators who oversee the Treasury Department, it could take the IRS up to 20 weeks to finish sending stimulus checks out to all eligible Americans. Though many citizens received their money through direct deposit as the IRS began making payments the week of April 13, paper checks didn’t begin going out until May 4. The IRS said in late May it was also still sending out payments using prepaid debit cards.

The IRS Doesn’t Have Your Current Banking Information

Payments sent out through direct deposit relied upon the banking information Americans provided when they submitted their 2018 or 2019 taxes. However, not everyone chooses to receive their tax returns through direct deposit—and the banking information from 2018 isn’t guaranteed to be up-to-date, either. In those cases, the IRS encouraged Americans to either sign up for direct deposit by May 13 or wait to receive a physical check or prepaid debit card in the mail.

You Used a Tax Preparation Service to File Your 2018 or 2019 Taxes

In April, the IRS said it was aware of an issue some Americans who had used tax preparation services were facing in receiving their stimulus checks. In those instances, the payment was sent to a bank account associated with the service before it could be sent to the intended recipient in what the IRS said was a typical occurrence during normal tax filing procedures. When this happens, the IRS said the bank linked to that intermediary account would reject the payment and return it to the IRS, which would then send the stimulus payment out again as a physical check.

You Submitted a Disqualifying Form as Part of Your 2019 Taxes

Americans who filed any of four forms as part of their 2019 taxes were disqualified from receiving a stimulus check. Forms 1040-NR and 1040NR-EZ, both of which apply to nonresidents, both disqualified individuals from receiving a $1,200 check, as did the self-employment forms 1040-PR and 1040-SS.

You Aren’t Typically Required to File Taxes

U.S. residents who don’t usually file taxes—including full-time college students, unemployed Americans, and Americans who do not work and retirees who receive Social Security benefits—must complete a non-filers form in order to alert the IRS that they are awaiting their stimulus payment.

You Are Behind on Child Support Payments

According to a mid-May IRS news release, taxpayers who are behind on their child support payments won’t necessarily receive their full stimulus check amount. The agency said past-due child support would be taken out of the payment, though the recipient is expected to receive an alert from the Bureau of the Fiscal Service if this happens.

You Owe Money to Creditors

The IRS said it is unable to protect stimulus payments from creditors, who may take money out in garnishments once an individual’s payment is deposited. According to the IRS, the checks “are not protected from garnishment by creditors by federal law once the proceeds are deposited into a taxpayer’s bank account.”

For everyone else who qualifies for a stimulus check but still hasn’t received one, the IRS has assured Americans that the payments are on the way. “Economic Impact Payments have continued going out at a rapid rate to Americans across the country,” IRS Commissioner Chuck Rettig said in a news release last week.

The IRS did not respond to Newsweek’s request for comment in time for publication.