From the U.S. Department of State:
The U.S. Department of State is pleased to use the occasion of Gay, Lesbian, Bisexual, Transgender Pride Month to announce its new policy guidelines regarding gender change in passports and Consular Reports of Birth Abroad.
Beginning June 10, when a passport applicant presents a certification from an attending medical physician that the applicant has undergone appropriate clinical treatment for gender transition, the passport will reflect the new gender. The guidelines include detailed information about what information the certification must include. It is also possible to obtain a limited-validity passport if the physician’s statement shows the applicant is in the process of gender transition. No additional medical records are required. Sexual reassignment surgery is no longer a prerequisite for passport issuance. A Consular Report of Birth Abroad can also be amended with the new gender.
As with all passport applicants, passport issuing officers at embassies and consulates abroad and domestic passport agencies and centers will only ask appropriate questions to obtain information necessary to determine citizenship and identity.
The new policy and procedures are based on standards and recommendations of the World Professional Association for Transgender Health (WPATH), recognized by the American Medical Association as the authority in this field.