Native New Yorkers who do not identify as neither male or female will now be allowed to check "X" on their birth certificate.
The New York City Council passed legislation Wednesday allowing the "X" marker to be added, in place of male or female, without clearance from a doctor or mental health professional.
City Council Speaker Corey Johnson, a Democrat, introduced the bill in June and applauded its passage.
"Today is a historic day for New York in its role as a worldwide champion for inclusivity and equality," he told the Associated Press. "New Yorkers will no longer need a doctor's note to change their gender on their birth certificates, and will no longer be treated as if their identity was a medical issue."
Under the bill, parents can also select the "X" or the non-binary option for their newborns.
Democratic mayor Bill De Blasio backed the policy noting that it will "allow transgender and gender non-conforming New Yorkers to live with the dignity and respect they deserve."
However, Dr. Paul McHugh, a Johns Hopkins psychiatrist, says identifying as transgender can lead to "grim psychological outcomes."
"Policymakers and the media are doing no favors either to the public or the transgendered by treating their confusions as a right in need of defending rather than as a mental disorder that deserves understanding, treatment, and prevention," he wrote in The Wall Street Journal.
In 2015, Peter Sprigg, Senior Fellow for Policy Studies at the Family Research Council, told CBN News that introducing that concept to children will only cause confusion.
"It's challenging enough for normal children to navigate and come to terms with their gender, identity, what it means to be male or female," he said.
"Things like this are only going to create greater confusion, add greater confusion to the struggles that in the ordinary course of things most children will have," Sprigg added.
De Blasio is expected to sign the bill, which will go into effect January 1.
New York City will now join Oregon, California, Washington and New Jersey in allowing the third gender option on birth certificates.