To apply for a replacement for your current U.S. adult passport, you will need:
Your most recent U.S. passport
The $75 application fee
Two recent identical color photographs. They must be two inches by two inches (5cm x 5cm) and the size of the head (from hair to chin) must be between .75 inches and 1 inch (2.5 to 3.5cm). The background must be plain and light-colored.
If your most recent passport was issued when you were 15 or under, you will need to complete the DS-11 application form instead of the DS-82. The fee for the service will be $100.