Coronavirus stimulus payments have been hitting bank accounts and mailboxes for several weeks now. These COVID-19 relief payments meant to help families during the great lockdown are valued at up to $1,200 per adult and $500 for each dependent child.

If you've received your money but got less than you expected, you aren't alone. Unfortunately, there are two key reasons why your stimulus check may be smaller than you were hoping for. 

1040 form with check from the U.S. treasury sitting in front of it.

Image source: Getty Images.

1. The IRS doesn't know about your dependents

For each eligible dependent child under 17, you should get an additional $500 in COVID-19 stimulus money. If you didn't get the extra money for your kids, your payment will be much smaller than anticipated.

The IRS may not know to send money for your dependents if:

  • They weren't declared on your most recent tax return. The IRS will get your information from either your 2018 or 2019 tax return. If you adopted a child or had a baby in 2019 but didn't file a return for that year yet, the IRS won't know it. Likewise, if your new family member didn't arrive until 2020, the IRS won't be aware. 
  • The IRS got your info from the Social Security Administration or Veterans Administration: If you don't file a tax return but you receive SSI benefits, Social Security Disability benefits, survivor benefits, retirement benefits, railroad retirement benefits, or veterans benefits, the IRS can get your info from the Social Security Administration or VA. This won't have details about your dependents, though. 

Remember, only children under 17 who are related to you by blood or marriage and who you can claim as a dependent on your tax return are counted. If you are claiming a college student or disabled adult relative as a dependent, you won't get the stimulus money for them. 

2. The IRS considered your income from a different year than you expected

Your check might also be smaller than you anticipated if the IRS is looking at a different year's income than you expected.

Full stimulus checks are available only if your adjusted gross income is below $75,000 for single filers and $150,000 for joint filers. For each $100 above the income limits, the amount of your stimulus check is reduced by $5. 

Let's say you made below the $75,000 threshold amount in 2019 but above it in 2018. If you submitted your 2019 return only recently and expect your check amount to be based on 2019's adjusted gross income, you're probably expecting the full check. But if the IRS processes your COVID-19 stimulus payment before processing your 2019 return, it will base the amount on your higher 2018 income and you'll see a reduction.

What should you do if you get less than anticipated?

Unfortunately, if your stimulus check is too small, there's nothing you can do immediately to correct the problem. You'll just have to make do with the lower-than-expected payment. 

You can eventually get any extra money that's owed to you -- but you'll have to file your 2020 tax return to do so. Since the IRS won't begin accepting those until the end of January 2021, you will have a long wait before the stimulus money is available to use or invest.

And, of course, the relief amount you are actually due is supposed to be based on 2020 adjusted gross income when you file as it was technically a credit advanced toward your 2020 tax filing (and only used the earlier filings as a way to help expedite the payment). So if your earnings in 2020 have gone above the limit, you still may get less than you would have if they'd been able to base the check amount on your lower earnings in 2018 or 2019. But the funds will not need to be returned if your 2020 adjusted gross is above the limit.