Gov. Jerry Brown of California. Rich Pedroncelli/AP Next year, California will begin legally recognizing a third gender for state residents who do not identify as male or female.

Democratic Gov. Jerry Brown signed the Gender Recognition Act on Sunday to make it easier for people to change their gender on state identification cards and birth certificates, and to add a "nonbinary" option, the Sacramento Bee reported.

The new law—which will take effect on Sept. 1, 2018—defines the designation of "nonbinary" as an "umbrella term for people with gender identities that fall somewhere outside of the traditional conceptions of strictly either female or male."

This classification includes but is not limited to some transgender individuals, those born with intersex traits, those who use gender-neutral pronouns, and those who describe their genders as "agender, genderqueer, gender fluid, Two Spirit, bigender, pangender, gender nonconforming, or gender variant."

The bill will also make it easier for residents to change their gender to male or female, eliminating the need for a court order or proof of clinical treatment to apply for gender changes. Advocates of the law say this change will expand rights for California's LGBT community, the Bee noted.

Past law required an individual to have undergone some sort of treatment for the state to recognize a change of gender on official documents such as a state ID or birth certificate.

The new bill requires that "the state registrar shall issue a new birth certificate reflecting a change of gender to female, male, or nonbinary without a court order for any person born in this state." Residents just need to submit an application to the registrar and an affidavit attesting that the request is not made for any fraudulent purpose.

A sign protesting a recent North Carolina law restricting transgender bathroom access at the 21C Museum Hotel in Durham, North Carolina May 3, 2016. Jonathan Drake/Reuters

Jody Herman, an expert on gender identity law and policy for the Williams Institute at the University of California, Los Angeles, said that Oregon, Washington, D.C., Australia, New Zealand, Nepal, India, Pakistan, Thailand, and parts of Canada have already adopted some form of legal recognition of a third nonconforming gender.

"California is a large state and if we can make these changes to our administrative system, then certainly other states are capable of doing that," Herman told the Bee. "As gender identities continue to expand and our concepts of gender continue to expand, governments are going to have to grapple with it and figure out how to be responsive to the way people understand themselves and live their lives."

Randy Thomasson, president of the pro-family organization SaveCalifornia.com, released a statement in opposition to the new law.

"Pushing so-called ‘nonbinary' upon 15-year-olds applying for a learner's permit or 16-year-olds getting their drivers' licenses tells them a big lie about sex," Thomasson said. "It's an unchangeable law of Nature that you're male if you've inherited a Y chromosome from your father; if not, you're female."

"Now that Governor Brown has signed this illogical bill, parents will have to work even harder to teach their children the reliable facts of life," Thomasson said.