Washington state and Pennsylvania will offer a third gender option on driver's licenses, so people who don't identify as female or male can choose X instead.
The changes will bring the number of states that offer a third option to at least 14. Washington, DC, and New York City do, as well.
"Identity is a fundamental human right," Washington state's Department of Licensing Director Teresa Berntsen said in a statement released by Gov. Jay Inslee, a Democrat.
"The driver's license or the state-issued ID cards are your primary identification documents. So by us acknowledging there are more than two forms of gender, we are acknowledging basic human rights," said Berntsen, whose department will hold public meetings to get feedback on proposed language for the rule change.
The third option for gender could be available as early as October, Inslee said in the statement.
In Pennsylvania, the third gender option is "something that's been on our radar and people have been asking for," state Department of Transportation spokeswoman Erin Waters-Trasatt told CNN.