Does Iowa Laws allow transgender men to use a woman's restroom?

Well, a transgender man would be someone who was born female and has transitioned to male. It wouldn't make much sense for him to use the women's restroom. Someone born male who has transitioned to female is a transgender woman.

Effective July 1, 2007, the Iowa Civil Rights Act (Iowa Code Chapter 216) was expanded to add sexual orientation and gender identity to the list of protected characteristics. Transgender people use the bathroom which matches their gender identity.