Montana Gov. Gianforte signed SB 458 defining sex as binary, eliminating legal recognition of transgender and intersex residents
On May 20, 2023, Montana Gov. Greg Gianforte signed Senate Bill 458 into law, inserting binary, reproduction-based definitions of "male," "female," and "sex" into roughly 40 sections of state code. The statute defines sex strictly by chromosomes and gamete production "under normal development," eliminating legal recognition of transgender, nonbinary, and many intersex Montanans on documents such as birth certificates and driver's licenses. The bill, drafted in part by the Montana Family Foundation, passed the Legislature largely along party lines.