US passports are valid for 10 years from the date they are issued. It seems logical, then, to assume that you should renew your passport two or three months before it expires. In fact, you may need to start the renewal process as early as nine months before your passport's expiration date.
If you are considering a vacation abroad, you should be aware that many countries will not allow you to cross their borders unless your passport is valid for six months beyond your initial date of entry. Still more, including the 25 European nations that participate in the Schengen accord, require your passport to be valid for at least three months past your date of entry. A few countries have a one-month validity requirement.
According to the US Department of State, it takes four to six weeks to process an application for a new passport or passport renewal, and half that time if you pay for expedited processing and overnight delivery of your application and new passport.
To determine when to apply for a new passport or renew your existing passport, you will need to determine the entry requirements for the countries you plan to visit, then add at least six weeks to the passport validity requirements for your destination.
If you are planning to travel overseas, check to see if your destination country has specific requirements for passport validity by clicking on the links below.