ASCE 31 uses "Level of Performance" in lieu of "Occupancy Category". ASCE 31 only includes Life Safety and Immediate Occupancy and typically Occupancy Category III structures would fall somewhere in between. The IEBC has some discussion on how to Consider these structures.
Many people use...
Are you looking at frame columns sitting on a mat foundation? A large pier/pile cap? If you are modeling a mat/pile cap in SAFE, for example, how much do the moment magnitudes depend upon the size and aspect ratio of your elements?
(slightly off topic) When you have a "pinned" baseplate...