Stimulus check: Why your "plus-up" payment might not be as big as you expect

Some people are in line to get extra money if they didn't receive what they were entitled to from the three stimulus checks so far authorized by Congress. But the IRS is cautioning that some people may not get what they expect. 

These so called "plus-up" payments are now being sent by the IRS to people who didn't get their entire payments from the three checks, which each have their own eligibility thresholds and payment amounts. The tax agency said it is now sending out extra payments as it processes 2020 tax returns, which may indicate some people are owed more money. For instance, each stimulus payment provides money for dependent children, but people who had children in 2020 might not have received all three payments for their kids. That's because the IRS has relied on a family's most recent tax return to determine their payment — and the first two payments were issued before the 2020 tax season began. That means the IRS would have relied on 2019 returns for the first two checks, and, because it would not have known about a child born in 2020, it wouldn't have sent those payments.