State of Missouri. My lawyer sent me a draft proposed settlement for my feedback and it stated that I'd have to pay child support until our kid is 18 unless he goes to college in which case it continues until 21 or he graduates (whichever is sooner). I asked my lawyer why and he said that's what the judges in our county always mandate.

Then, before we'd sent ours over, her lawyer sent their purposed settlement which basically said the same thing except it included trade schools too.

My only consolation is that it sounds like I can write up the settlement and negotiate such that my child support can be paid directly to my son once he's 18 instead of paying to my STBX - which I will 100% do. Still seems stupid that it doesn't end at 18 no matter what.