Robot Masters listed by their serial numbers.

Most Robot Masters possess a unique identification code, consisting of a two-letter "series code" followed by one of N, No, or #, then a three-digit "serial number". Robot Masters who do not have a serial number or whose serial number has yet to be revealed include: Quint, King, Sunstar, Dark Man, Doc Man/Doc Robot, Fake Man, and Mega Man X.

Robot Masters who had their serial numbers revealed in other media include Time Man - DLN-00A (Mega Man (Archie Comics)), Oil Man - DLN - 00B (Mega Man (Archie Comics)), and Quake Woman - LMN-001 (Mega Man (Archie Comics)).