Know Your Destination Country Documentary Requirements
Beginning January 31, 2008, Students 19 years and older who wish to cross over into Mexico either at Matamoros or Progresso, will need to present the following:

1) Government issued photo ID, (such as a driver's license as proof of identity),
2) Along with proof of citizenship, such as a birth certificate or a passport.

Students age 18 and under will be able to enter with proof of citizenship.
Verbal claims of citizenship and identity alone will not be sufficient to establish identity and citizenship for entry into the United States.

Please be sure to visit CBP.gov for updates on travel documents and details as to when new requirements will go into effect.