People born in New York City who don’t identify as male or female will have the option of changing their birth certificates to “X” under legislation passed Wednesday by the City Council.

The bill adopted by a 41-6 vote will also allow parents to choose the designation for their newborns, and it will permit adults to change the gender on their birth certificates without an affidavit from a doctor or mental health professional.

Some states including California, Oregon and Montana allow individuals to change the gender on their birth certificates without a note from a doctor, but it’s unclear how many jurisdictions allow parents to select a nonbinary option for their newborns. The option could be used by parents of intersex children or by parents who want their child to be able to choose a gender at a later date.

Democratic Mayor Bill de Blasio is expected to sign the bill, which will go into effect Jan. 1.

Prior to 2014, New Yorkers seeking to change the gender on their birth certificates had to have undergone gender confirmation surgery first.

Legislation Johnson introduced then allowed people to change their birth certificates without surgery but left the requirement for a doctor’s note in place. The new law eliminates it.