So I got a tax form from my kids school showing tuition payments

I also got a 529 tax form from distributions.

Do I reduce the tuition expense by the 529 distributions, not sure what to do?

I'm not a tax expert, but I've done a lot of tax returns as a VITA volunteer, and my understanding is that if your 529 withdrawals were for valid educational expenses, then you owe nothing to taxes on your withdrawals.

The most common problem I see with 529 distributions is timing of the withdrawal. Many people won't get around to doing their expense tally until January for Fall expenses. So you get a form from the school showing education expenses in 2020, but the 1099-q from your broker shows a 2021 withdrawal.

Turbo tax can't process this in "easy" mode. I've heard mixed answers from CPA's about it - grey area supposedly. I strongly recommend taking 529 distributions in the same calendar/tax year as the expense.

I take care of this by budgeting for the year.

I project what I will spend, take my withdrawal and then disburse it as needed. If I'm short, Its not by much and I cover it out of pocket,

The chances of being over are practically nil as you can nearly always find something that meets the QEE classification.