The rule in New York State is that you can do a total of up to 12 weeks of rotations in hospitals that are not affiliated with your school. You also have to apply for a letter of eligibility from the state medical education board (this is separate from the one that you have to get before doing rotations in an affiliated hospital; do this a few months before the start of your rotation and hound them if you don't get a response within 6 weeks). The only exception to the 12 week rule is rotations done in VA hospitals, but you should look further into that. Unfortunately, as far as I know Wyckoff is the only hospital affiliated with our school. Somehow St. Matthew's managed to get an affiliation with Mt. Sinai so I think they can do unlimited rotations there.