Travel to Cuba is like travel to any other country that requires a visa for U.S. passport holders. It is upon return to the United States where travelers must be able to comply with Department of the Treasury regulations or face possible civil penalties and criminal prosecution.
The Cuban Assets Control Regulations are enforced by the Office of Foreign Assets Control (OFAC) of the U.S. Department of the Treasury and affect all U.S. citizens and permanent residents. The regulations require that people be licensed in order to engage in any travel-related transactions for travel to, from, and within Cuba. U.S. law enforcement authorities enforce these regulations at U.S. airports and pre-clearance facilities.
OFAC recently issued new regulations for academic travel to Cuba and will be issuing additional guidelines within the coming weeks. According to the NAFSA's Resource Library the new regulations allow accredited U.S. institutions of higher education to sponsor travel to Cuba for course work for academic credit under a general license. They allow accredited U.S. graduate or undergraduate degree-granting academic institutions to sponsor or co-sponsor academic seminars, conferences, and workshops related to Cuba or global issues involving Cuba, by specific license. Regulations specify that students/ faculty/ staff participating on such programs will be required to carry letters “stating that the Cuba-related travel is part of a structured educational program of the sponsoring U.S. academic institution, and stating that the individual is a member of the faculty or staff of that institution or is a student currently enrolled in a graduate or undergraduate degree program at an accredited U.S. academic institution and that the study in Cuba will be accepted for credit toward that degree".