If a person neither identifies himself as a male or a female, they can choose to be identified and marked as ‘X’ on their legal documents. Unfortunately, the United States only has two sex makers available for the U.S. passport. They are M for Male and F for Female. Even though you may have other documents such as birth certificate, driver’s license, court order or other documents in non-binary, you will not be able to have a non-binary gender identified on your passport.