The U.S. Embassy and Consulates General accept and process applications to renew expiring or expired passports. Adults who can present a previous passport that was issued within the previous 15 years, and who were at least 16 years old when the previous passport was issued, should submit:
Non-emergency passports will be issued in the United States and sent back to the Embassy via courier. The turnaround time is normally five to seven business days.
If your current passport expires in two years or less, you can fill out form DS-4085 and continue to use your current passport until it expires. Even after you receive your new passport, you will be able to use your current one (i.e. you will have two passports at the same time). This service is free.