When is the last day to enter the US without a passport...traveling to Mexico?

All 3 answers are WRONG!!!!! The ONLY thing has has changed now is that they are enforcing the requirement to have a birth certificate as well as a photo I.D. Passports are NOT needed for LAND travel to and from Mexico yet . That has NOT CHANGED! The date has NOT been set. See site below for the CURRENT info...the date will be start "LATER". Passports have been needed for over a year to FLY to and from Mexico. The amount of MISINFORMATION out there on this subjuect is amazing. Just read top half of page below carefully to get the facts.

Jan 31

Jan 31. You will need a pastport as that date has now gone.

It already past ... you now need a US passport to travel to and from Mexico.

Edit: According to the U.S. State Department Website it specifically states, "Land or sea travelers must have a valid U.S. passport [to enter the United States] ..." I think thats rather unambiguous of a statement. Granted, it does state one can use official copies of citizenship documents such as a birth certificate or naturalization certificate in conjunction with a valid photo ID, but I can tell you two things about that. 1) Official copies of those documents are sometimes just as expensive as the application fee for a passport, so why not just file for a passport and save yourself the grief. And 2) if you show up at the border with a birth certificate and a valid photo ID in lieu of a passport they're going to send you to the "special line." That means it will takes you a lot longer to get back into the country, because they have to verify you are who you say you are ... if you have a passport they just swipe it through their reader and you can go on about your business.

Technically you can travel internationally by air under the same conditions ... you do not need a valid passport, but I can tell you right now just because you can technically do something doesn't mean its a good idea. I think everyone can agree you need a passport to fly from Los Angeles to Paris, just because there's a clause that states you can use alternate identification doesn't mean its just as efficient, or advisable.