Why us my return being offset for my stupid ex husband's child support? He's not even on my return, had 0 income, and is jail Why do I still have to claim injured spouse?

If he is your

EX

- husband how did you file?   If you are divorced you should be filing Single or Head of Household--not married.  Why are you filing injured spouse---you only file injured spouse when you file a joint return with someone you are legally married to.

Did you file a joint return in either 2018 or 2019 ?  If so he is on the return so you will have to file the injured spouse form each and every year you file jointly.