Find evidence of U.S. citizenship. Applicants will need a copy of their birth certificate, a previous passport or certificate of naturalization in order to apply for a U.S. passport. This is one of the two forms of identification needed for obtaining a passport.
Bring valid photo identification such as a driver's license or state identification card. The city of Sacramento also requires you to have a photocopy of the front and back of the identification.
Get a passport photo taken. This can be done as a last step in the city clerk's office for $15 (as of 2010) or more cheaply at a local drugstore or other location that offers the service.
Complete the application (Form DS-11 - Application for U.S. Passport), but do not sign it. A clerk must be present for the signature to be valid. The form can be found online or picked up at the city clerk's office.
Make an appointment at the passport office if possible. This is strongly recommended if you're going to the city clerk's office, although the office does accept walk-ins.
You can also go to a local post office that offers passport processing and turn in information there if it is more convenient
Pay the required fees at the office. Credit cards are not accepted so bring cash, money orders or checks. Current application and execution fees can be found at travel.state.gov.
