Planning a trip outside the US? You had better have a passport.
Starting Tuesday, new State Department rules go into effect that requires travelers to have passports for places like Canada, Mexico and the Caribbean.
For years, just a birth certificate or driver's license was required.
The rule may be a hassle for some, but others support the new security measure.
Guy Enderle is a traveler. He said, “Anything that's going to slow down the flow of people from that part of the world. It's an area I believe we're a bit more vulnerable from."
So what happens if you travel without a passport and try to re-enter the US?
Homeland Security says you will have to undergo a secondary screening to verify your citizenship.
Right now, only 27% of Americans have passports.
For now, the rules only apply to air travelers.
But by 2008, all travelers will need a passport.