Upon arrival in Sint Maarten, you must have:
a U.S. passport valid for the duration of your stay;
an Embarkation and Disembarkation Card (ED-Card);
a return or onward ticket;
proof of accommodations (hotel reservation, property ownership, or the address of a family member or friend if you are not staying at a hotel); and
proof of sufficient funds to cover expenses during your stay ($100 – $200 U.S.D per day or valid credit card).
U.S. citizens are allowed to stay in Sint Maarten for a maximum of six months with the possibility to extend. For more information about entry requirements, duration of stay, and extensions, visit The Sint Maarten Travel Guide or contact the Sint Maarten Immigration and Border Protection Service (IBP) directly at firstname.lastname@example.org or +(721) 543-0355.
Additional sources of information include: The Official Website of The Government of Sint Maarten; The Royal Netherlands Embassy (4200 Linnean Avenue NW, Washington, DC 20008, telephone (202) 244-5300), and the Dutch Consulates in Chicago, Miami, New York, and San Francisco.