Do I need a new I-20 each time I enter the US for a residency? What if my F-1 student visa is still valid?

Yes. A new Form I-20 must be obtained, and a new SEVIS fee payment made, for every residency regardless of whether you already have an F-1 student visa. This is because the SEVIS payment is attached to the Form I-20 and the Form I-20 expires after the last day of each residency.

If your F-1 student visa is valid through the dates of your last intended residency, you do not need to obtain a new F-1 student visa for your other residency locations.

Please see the attached file for complete information about the process for international students attending residencies in the U.S.