Can you claim a second qualifying child with $0 in child care expenses to increase your credit even if the second qualifying child is not in child care?

Yes, you can do that. The limit on child care expenses that you can use for the child care credit is a total of $6,000 for two or more children. It doesn't matter how much is spent on each child. You can spend $6,000 on one child an nothing on the other child.

Yes, that is a curious twist in the calculation of dependent care benefits. When you go through the interview for dependent care benefits (which ends up being form 2441), you can claim a second child (if you have an eligible one) in the calculation, even if none of your benefits were spent on that child.

Look at Question 9 on "Child and Dependent Care Credit FAQs".

[Edited 2/13/2025 10:04 PST to update link above]