A bill signed into law this week gives New York City residents the opportunity to change the gender on their birth certificate to a third, gender-neutral option.

The bill allows residents who don’t identify as either male or female to change the gender on their birth certificate to “X," and also allows parents of newborns to choose the “X” option for their child.

NEW YORK CITY PROPOSAL WOULD ALLOW ADULTS TO CHOOSE GENDER 'X' ON BIRTH CERTIFICATES

In addition, the bill removes the requirement that residents need an affidavit from a doctor or mental health professional to change the gender on their birth certificates.

De Blasio said the third option is a way for residents who don’t identify as male or female to tell the government who they are -- “not the other way around.”

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The bill, which goes into effect on Jan. 1, comes after the city proposed the change in June.

California, Oregon, Washington state and New Jersey also allow a third gender option on birth certificates, while Washington, D.C. allows gender-neutral driver licenses.

The Associated Press contributed to this report.