Do I Need a Passport for Puerto Rico?
This is a question that I see over and over in various forums etc. This questions arise because of the new Western hemisphere Travel Initiative that was implemented at the beginning of the year.
The bottom line is ‘NO YOU DO NOT NEED A PASSPORT’ if you are a US citizen or legal permanent resident and you are traveling to or from Puerto Rico from the mainland United States or one of its territories (Guam, Puerto Rico, the U.S. Virgin Islands, American Samoa, Swains Island and the Commonwealth of the Northern Mariana Islands).
See this site http://travel.state.gov/travel/cbpmc/cbpmc_2225.html#1 for further information.
Here is an extract from that page:
Q. Will travelers from U.S. territories need to present a passport to enter the United States?
No. These territories are a part of the United States. U.S. citizens returning directly from a U.S. territory are not considered to have left the U.S. territory and do not need to present a passport. U.S. territories include the following: Guam, Puerto Rico, the U.S. Virgin Islands, American Samoa, Swains Island and the Commonwealth of the Northern Mariana Islands.
Hope this helps.
Disclosure: this is my interpretation of the new rules and you should review the above site and contact the State Department or your airline company for more detailed information.