Washington, D.C., this week will become the first jurisdiction in the U.S. to offer a driver’s license reading “X,” instead of “M” or “F.”

The D.C. Department of Motor Vehicles worked with the National Center for Transgender Equality to implement the new option. It follows a wave of court orders in the past year that have designated at least 20 people legally non-binary, challenging the available options for gender on identification documents.

“Washington, DC has long been a leader in LGBTQ rights and gender issues, and this change is the most recent example of our city’s commitment to inclusivity,” D.C. Mayor Bowser said in a statement Friday. “The safety and well-being of all Washingtonians is my top priority, and whenever we are presented with an opportunity to improve the lives of residents and better align our policies with DC values, I will take it. I hope to see other jurisdictions follow in our footsteps.”

The DMV is closed on Monday, so the first available opportunity to get an ID reading “X” is Tuesday.

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Advocates say the new option will be helpful for non-binary and trans people for whom neither “M” nor “F” are accurate options. Elizabeth Ehret, an Equal Justice Works AmeriCorps Legal Fellow working at Whitman-Walker Health, became involved with the change after a client came to the health clinic in February and asked if they could get a non-binary marker on their ID.

“I talked with them and I said, ‘Look, this is not something that’s currently available in D.C. but we can see what we can do,’” Ehret said.

Since then, the client has been part of the DMV discussions, Ehret said. Representatives from Whitman-Walker Health and National Center for Transgender Equality also worked with the DMV to implement a self-attestation form, which will allow residents to self-attest to their gender while changing the sex marker on an ID. Until recently, D.C. residents had to receive a signature from a health provider before they could do so.

Ehret said the new option will be important for D.C. residents who currently use an ID that is incompatible with their appearance or identity. Doing so, she said, can put trans and non-binary people at risk for harassment or violence. “People are going to have access to a gender marker that actually matches their gender identity,” she said.

Advocates also say that allowing residents to self-attest to their gender will remove barriers for people who want to change their IDs, but previously lacked access to a health care provider who could sign off on the change.

On June 20, Ward 1 Councilmember Brianne Nadeau introduced a bill that would enable people applying for driver’s licenses, permits and other identification cards to list their gender as “nonbinary.”

The bill is “complementary” to the DMV’s efforts and would ensure that the change would not be undone by a future administration, said Tom Fazzini, Nadeau’s deputy chief of staff and communications director.

D.C. is set to begin issuing “X” licenses about a month before Oregon begins making the same change. In June 2016, Portland resident Jamie Shupe became the first legally non-binary person in the U.S., spurring a year-long process by the state’s DMV to create a non-binary option for licenses. Shupe was followed by others in Oregon and California who obtained similar court orders to become legally non-binary.

The Oregon DMV met with other state agencies and non-binary residents before its transportation commission unanimously voted this month to approve the new option. State lawmakers in the California Assembly are also considering a bill that would add a non-binary option on driver’s licenses, which passed the state Senate last month.

Shupe, who grew up in Maryland and served in the military before moving to Oregon in 2014, applauded the change in an email.

“I literally fled to Oregon, because I felt not only unsafe, but I also felt just flat out unwelcome on the East Coast as a non-binary transgender person,” Shupe wrote. “D.C., the place of my birth, has given me tears of joy by their actions.”