If your application for a student visa is approved, the consular officer will place a visa sticker or stamp in your passport and return the I-20 or DS-2019, often in a sealed envelope.  With these documents, you may enter the U.S.

When you arrive at a U.S. port of entry, you will be required to present either your Form I-20 or Form  DS-2019, along with your passport and financial documents, to the immigration officer. The immigration officer will keep one copy of your form and stamp another copy and return it to you. He or she will also issue a completed I-94 Arrival-Departure  Record. The I-94 is an extremely important document, which indicates the date when your permission to remain in the U.S. expires.  It must be kept in your passport. F-1 students will be returned page 3/4 of the I-20, called the I-20 ID copy. The I-20 ID copy is the permanent record of your permission to enter and remain in the U.S. and must be kept in your possession as long and you are a student. J-1 visa holders will receive the pink copy of the DS-2019.

CANADIAN CITIZENS
Canadian citizens are not required to have a U.S. visa to enter the United States.  You must present your I-20 (or DS-2019) form and proof of financial support at the U.S. port of entry.  The INS inspector will stamp your I-20 (or DS-2019) and issue you an I-94 card that indicates that you are in F-1 (or J-1) status.  It is critical that you enter the U.S. in student status to be eligible for the benefits of that status, including on-campus work permission, optional practical training etc.   If you enter the U.S without any documentation, you are assumed to be in tourist/visitor status and are not entitled to these benefits.

Transfer Students
For those of you who are attending a U.S. institution prior to coming to Yale, you can complete your immigration status transfer  process by either re-entering the U.S. on Yale’s I-20 or DS-2019 form, or, if you do not leave the U.S., by reporting to OISS  with your immigration documents.  You must report to OISS within 15 days after the first day of classes.  Please bring with you your immigration documents (including the I-20 issued by Yale) and proof that you were a full-time student at your previous school (e.g. school transcript, letter for international student or academic adviser.)  Failure to do so will result in the loss of your F-1 or J-1 student status.