I received a CP11 notice saying they changed the amount claimed as nonrefundable Child Tax Credit or credit for other dependents because I either didn't enter an amount or entered an incorrect amount based on the number of boxes checked on page 1 of return.
I don't understand that because I claimed 2 dependents everywhere. But what's really confusing me is that they changed the amount by $250.40 instead of $500 or $1000.
What could have happened to calculate such a seemingly odd number?
Assuming this was for tax year 2021:
You said in a comment that your joint income was below $200,000. However, the first phaseout of the child tax credit begins at $150,000 for married filing jointly. After that point, your child tax credit gets reduced by $50 (per child) for each $1,000 your income is above $150,000, until your credit is reduced to $2,000 per child. For example, if you have one child between the ages of 6-17, your child tax credit would normally be $3,000, but if your joint income was $155,000, the credit would be reduced by $250 to $2,750.
See this IRS FAQ on the calculation of the child tax credit for more details.
The amount of the tax credit is calculated on Schedule 8812.
The amount you see on your CP11 notice probably also includes some penalties and interest that were also assessed as a result of your tax calculation mistake, which could be why the difference you are seeing is not a multiple of $50.
