Visas and Entry into the US
If you are living outside the US you must obtain a passport from your government (if you don't have one already) and then take the I-20 or DS-2019 and supporting documentation to the nearest US embassy or consulate to apply for an F-1 or J-1 visa. Apply for the visa as early as possible. You can check the visa appointment and processing wait times for all US embassies and consulates. Students applying for initial entry F-1 and F-2 visas may be issued the visas up to 120 days before the academic program start date as noted on the I-20. J-1 and J-2 Exchange Visitors may be issued visas at any time before the beginning of their programs. (Canadian citizens do not need a visa, but simply present the I-20 or DS-2019 to the immigration officer at the US port of entry. A passport may be required depending on your method of travel.)
You may not enter the US earlier than 30 days before the start date noted in Item 5 on the I-20 form or Item 3 on the DS-2019 form. You should make your travel arrangements with this date in mind. Your I-20 or DS-2019 does not require a travel signature for your initial entry into the US. However, you need a travel signature for subsequent trips. The ISSS advisor cannot sign your document until you have registered full-time for your first quarter. Do not plan to travel outside the US after your first entry unless you will be able to register first and obtain a travel signature.