By now, most Americans have received coronavirus stimulus payments via direct deposit or mail. And for those still waiting, payments should be coming soon. 

These COVID-19 stimulus payments are worth up to $1,200 per eligible adult and $500 per eligible dependent child, with the amount you'll get based on income. But for some Americans, the amount they've received isn't as expected.

If that's happened to you, the IRS has a list of six likely reasons. Here are details on whether the problems are fixable and how to get more money if they are. 

IRS building with stoplight in front of it.

Image source: Getty Images.

1. Your check wasn't based on your 2019 tax return

The deadline for 2019 tax returns has been pushed to July 15, and many people haven't filed them yet. And the IRS is behind on processing returns that have been filed. 

If your 2019 hasn't been processed, your payment will be based on the return you submitted in 2018 (assuming you sent one in that year). If your life changed between 2018 and 2019 in a way that affected your payment (such as a decline or increase in income or adding a new dependent child), the IRS won't know that.

If things changed in a way that should've resulted in a smaller stimulus payment, you won't have to pay back any excess you received (unless you got a payment for a deceased relative). And if you are entitled to more stimulus money than you were sent, you can get the extra when you file your 2020 tax return next year. 

2. Your dependents don't entitle you to $500

Your dependents qualify you for the extra $500 stimulus payment only if you'd be eligible to claim the Child Tax Credit for them. That means they must be related to you, live with you for at least half the year, and get at least half their support from you.

They also must be U.S. citizens, permanent residents, or qualifying resident aliens and must be under 17 at the end of whatever tax year the IRS is getting data from.

If your dependents don't meet all these requirements, you won't receive a $500 stimulus payment for them -- so you'll get less than expected if you weren't aware of this quirk of the CARES Act, which provided for the payments. 

Unmarried parents also can't both claim a child as a qualifying dependent. Whichever parent claimed the child in 2019 (or 2018) should get the money. But if the other parent is entitled to claim the child in 2020, they may be able to get the $500 when they file next year's return. 

3. Your dependents are in college 

The CARES Act excludes most college students from getting stimulus money. A college student who is legally an adult wouldn't get the $1,200 that's due to most adults if claimed as a dependent on a parent's return, but parents also wouldn't receive the $500 for them. 

Students who didn't get a payment and who aren't eligible to be claimed as a dependent in 2020 can file a tax return for this year, though, and should get their $1,200 credit then, assuming they meet the requirements to receive it.

4. Your dependents are too old or aren't your children

If your dependents were 17 or older during the 2019 (or 2018) tax season, you won't get the $500 for them. And they also won't get the money if they were claimed as a dependent. 

Other adult dependents, such as parents or relatives you're providing support for, also won't entitle you to $500 and won't get their own $1,200 checks. Like college students, though, they can claim them by filing a 2020 return if they're no longer classified as dependents this year. 

5. Your money was taken because you're behind on child support

The CARES Act stipulated that stimulus payments wouldn't be taken to satisfy most past-due debts owed to the government. You wouldn't have your money withheld if you owed unpaid student loan debt or back taxes, for example.

But if you owe past-due child support, the payment can be offset. For married couples filing jointly when only one spouse owes, only half of the family's stimulus funds should be offset if the person who doesn't owe filed an injured-spouse relief claim with their most recent tax return.

But in some cases, a glitch is resulting in too much money being withheld, and the IRS is working on fixing this problem. If you're affected, you just need to hang tight until the IRS works it out. 

6. Creditors garnished some of your funds

The CARES Act only prevented the seizure of stimulus funds for most debts owed to the government; other creditors can take the money after it's deposited in your bank account. If debt collectors took your COVID-19 money because you owed them, there may be very little you can do to get it back.

Make sure you get the money you're due

If you were paid too little because the IRS didn't know you have valid dependents or it used outdated income information, it's important you file your 2020 tax return to get the rest of the money you're owed.

You'll have to wait until the IRS begins accepting returns for this year, which likely won't be until the end of January in 2021. But at least the funds will still come eventually to help you cope with any financial loss the coronavirus has caused.