US citizens will have the option to choose the gender-neutral X marker on passports beginning April 11th, the Department of State announced. The agency said the X option will be available for other forms of documentation next year, according to a statement from Secretary of State Antony Blinken.

“After thoughtful consideration of the research conducted and feedback from community members, we concluded that the definition of the X gender marker on State Department public forms will be ‘Unspecified or another gender identity,’” Blinken said. “This definition is respectful of individuals’ privacy while advancing inclusion.”

The State Department first said last June that it would add a third gender marker to passports, but it didn’t provide a date when the change would take effect. It also announced that it would allow passport applicants to self-select their gender, without requiring medical evidence in cases where their gender did not match what was listed on other identification.

The Human Rights Campaign applauded the decision. HRC interim president Joni Madison said the update was one of several policy updates by the Biden administration “that will improve the lives of transgender and non-binary people in this country.”

The news comes on Transgender Day of Visibility, at a time when several state legislatures have taken up anti-transgender measures to try to prevent transgender children from receiving gender-affirming healthcare or playing on sports teams. A statement from the White House on Thursday condemned “the proliferation of dangerous anti-transgender legislative attacks,” adding that “the evidence is clear that these types of bills stigmatize and worsen the well-being and mental health of transgender kids, and they put loving and supportive families across the country at risk of discrimination and harassment.”

For details on how to apply for a passport with the X marker, visit travel.state.gov/gender.