Washington state allows 3rd sex option 'X' on birth certificates “Social norms are changing,” a state official said.

 -- Washington state will allow residents to change the sex on their birth certificates to a nonbinary option called “X.”

“Social norms are changing,” state registrar and Center for Health Statistics director Christie Spice told ABC News today. “When a person’s gender designation on their birth certificate doesn’t match how people present themselves, it opens the door to harassment and intimidation.”

The new rule, announced Thursday and effective Jan. 27, also removes the need for medical approval from a primary physician for adults who want to change the sex status on their birth certificate.

Minors who don't identify male or female and want to change their sex designation still need written consent from a parent or legal guardian and medical input. The difference now is that the list of health care professionals who can approve the change has expanded for minors to include primary physicians, physician assistants, psychologists, psychiatrists, social workers and mental health counselors, according to the state Department of Health.

People interested in changing their sex classification must complete a request, have it notarized and submit it to the health department.

Washington state has allowed residents to change their sex designation from male to female and vice versa for the past 10 years, Spice said, adding that the movement toward a third option stemmed largely from changing social norms.

“We received a couple of requests from residents but we were already in the process of discussing the new rule,” Spice told ABC News.

The Department of Health put the process in motion in August, followed by a public hearing in December. “[The hearing] was a packed house,” Spice said. “There were people on both sides of the issue but a majority supported the change.”

Some who argued against the rule said a birth certificate should only reflect information available at birth.

Other attendees discussed what some see as positive aspects of the new rule, such as freedom of expression and speech, as well as destigmatization.

The Department of Health also received about 1,000 written comments, Spice said. “We took every comment into consideration when we drafted the language for the rule,” she added.

The rule was signed by Washington Secretary of Health John Wiesman and officially adopted Dec. 27, but not publicly released until Thursday, a state official said.

Washington will be the second state to enact the third sex rule, after Oregon. California is also adopting the law, effective in September.