You will need to apply for a new passport if your passport has been significantly damaged, especially the book cover or the page displaying your personal data and photo. You will need to report your passport damaged and re apply for a new one. Water damage, a significant tear, unofficial markings on the data page, missing visa pages (torn out), a hole punch and other injuries may constitute “damage”. Normal wear of a U.S. passport is understandable and likely does not constitute “damage”. For instance, the expected bend of a passport after being carried in your back pocket or fanning of the visa pages after extensive opening and closing. In most cases of normal wear, you may renew your passport by mail.