State tax filing

Iowa has multiple filing status- go back to the start of the Iowa return and look for the screen below.  Here you must check the box "I need to change or verify my Iowa filing status (Select if married filing joint on federal)

If married taxpayers file a joint return

Both spouses are jointly and severally liable for the total tax due on the return, except when one spouse is considered to be an innocent spouse under criteria established pursuant to section 6015 of the Internal Revenue Code.