A change announced by the U.S. State Department last year adding a third gender option — “F,” “M” and “X” — to U.S. passports goes into effect today (Monday, April 11), with passport application forms on the State Department website now offering all three gender choices.

The State Department is the first U.S. federal agency to offer the X gender marker on an identity document.

The change came after Dana Zyym, an intersex and nonbinary Colorado resident, filed a lawsuit saying that with only the “F” and “M” options, it was impossible for them to get a passport accurately reflecting their gender identity, NPR notes. Zzyym received their passport with the “X” gender marker last December.

The “X” gender marker is officially defined as “unspecified or another gender identity.”

— Tammye Nash