Both the Katagiri clan in Toyoura, Soejimo County (present Toyoura-cho, Yamato-Koriyama City) and the Katagiri clan in Izushichijo, Soejimo County (present Izushichijo-cho, Yamato-Koriyama City) were branch families of the Katagiri clan in the Koizumi clan.
添下郡豊浦（現・大和郡山市豊浦町）の片桐氏及び添下郡伊豆七条（現・大和郡山市伊豆七条町）の片桐氏は、いずれも小泉藩片桐氏の分家である。