Consult the nearest embassy
If you are away from your native country and your United States passport is lost, you are required to contact the nearest US embassy. The issue needs to be reported as soon as possible in order to avoid any kind of a problem. The representative in the embassy will let you know how you can replace your passport.
Contact the State Department
If your passport is missing, you can contact the State Department by calling 1-877-487-2778. You may call at that number from Monday to Friday between 8AM to 10PM Easter Standard Time. Once you have called the State Department, your passport will be immediately invalidated and it would not be revalidated again.
Regional Passport Agency
You may visit a regional passport agency in person or any acceptance facility such as a post office. Report your stolen or lost passport and you will be issued a new passport after you have filled and submitted forms DS-11 and DS-64. These two forms are about Application for Passport and Statement Regarding Lost or Stolen Passport respectively.
In order to replace your passport, you will require the proof of citizenship (birth certificate with raised seal or Certificate of Naturalization), identification (ID card or Driver’s license, Social Security number as well as 2 passport photographs.
The fee for getting a US passport replaced is about $75, with $25 to the acceptance facility. In case you require an urgent passport, you would have to pay an additional $60. Keep in mind that they are not going to accept personal checks; therefore, you would have to pay in cash or through a credit card.
Take the forms to a post office
Once you have completed all these forms, you may take them to a local post office to begin the process.