New York City Mayor Bill de Blasio signed a bill into law Tuesday that will allow individuals to elect a third gender category on birth certificates issued within city limits, removing a number of medical and administrative barriers to doing so.

The bill was recently passed by the New York City Council, which worked closely on the bill with the city’s Department of Health and Mental Hygiene. The legislation will allow for a person’s legal gender to fall under the “X” category, a term which means that the individual’s gender is not exclusively male or female.

The law also allows for individuals who currently have their gender listed as “male” or “female” on their birth certificate to submit a signed and notarized statement attesting to their request for a change in gender to either male, female, or “X.” Previously, individuals who sought to have their gender changed on their birth certificates required affidavits from a licensed physician which stated that the new designation more accurately reflects the individual’s gender.

In a tweet, de Blasio stated, “The LGBTQ rights movement was born in NYC. Today, we’re making history again in the fight for dignity and respect.”

The bill was also praised by Toby Adams, the executive director of the Intersex & Genderqueer Recognition Project, a group that advocates for non-binary rights.

The bill will go into effect January 1.