This applies to ALL IMG schools, so I'm going to remove the same post from the Caribbean forum. In order to go the US (assuming you're a US citizen), you will need to take the USMLE Steps I, II CK and II CS. Steps I and II CK are written exams, Step II CS is a clinical skills exam. THAT'S IT. No more TOEFL or CSA. These steps bring you to your way for ECFMG certification.
If you are not a US citizen, you will also have to apply for visas (most commonly J1 and H1B) .