No U.S. Passport Required for Citizens of the United States!
When traveling from the United States to Puerto Rico, citizens of the United States are not required to carry their passport, although some form of government issued picture identification card is needed.
For travelers visiting from another country, other than the United States, a visa is required to enter the island. These requirements are standard and are the same as for entering the United States. The purpose and extent of your visit will determine which visa to apply for. Those coming in as a tourist will need to apply for the standard 90-day non-immigrant visa. Specialized visas are offered for those who are coming in for work or to study.