A few years ago Mount Sinai went on a shopping spree around Manhattan. When they did this they put their name on all the pre-existing residency programs at the hospitals they acquired. St. Lukes and Roosevelt Hospitals were included, as was Beth Israel. Icahn SOM now has 7 affiliated IM programs in the NYC area, 3 in Manhattan, 2 in Queens, 1 in the Bronx, and 1 in New Jersey. They run the gamut from a large academic university program (Mount Sinai main campus) to a small community program which is the only residency program based in the hospital (Englewood Hospital in New Jersey).
The 3 Manhattan programs are,
1. Mount Sinai - main university program. At Mount Sinai main campus on border of upper east side and east harlem. Very competitive.
2. Mount Sinai Beth Israel - community program with good academics (they consider themselves a university program due to historical reasons). Large community hospital (~900 beds) in Stuyvesant Town (east side at midtown/downtown border). Lots of in-house residency and fellowship programs. Moderately competitive IM program (mostly US MD, previously took lots of DO/IMG but not the case recently)
3. Mount Sinai St. Lukes/Roosevelt - community program with good academics. Split between 2 hospitals, St. Lukes (west harlem) and Roosevelt (midtown west). Lots of in-house residency and fellowship programs. Moderately/Minimally competitive IM program (mostly DO/IMG).