Most externships should be done before November if at all possible. This is helpful for you to get your letters of recommendation during your away rotation. However, there are some scenarios when an away rotation done later can be advantageous (i.e. November): 1) you do not necessarily need a LOR from that program; 2) you want to rotate at a program that you are very interested in after you have already "warmed up" at your other acting internships; 3) the program has a better chance of remembering you as the selection for interview process begins after the Dean's Letters go out (Nov. 1).
William N. Levine, MD
Associate Professor, Orthopaedic Surgery
Residency Director, Columbia University Medical Center