This book constitutes the refereed proceedings of the 6th International Conference on Abstract State Machines, Alloy, B, TLA, VDM, and Z, ABZ 2016, held in Southampton, UK, in June 2018. The 20 full and 11 short papers presented in this volume were carefully reviewed and selected from 60 submissions. They record the latest research developments in state-based formal methods Abstract State Machines, Alloy, B, Circus, Event-B, TLS+, VDM and Z.