The era of US state branching deregulation started in 1970 and ended up with the enactment of the Riegle Neal Act of 1994. One of the purposes of the branching restriction was to avoid bank concentration. The following paper addresses the influence of the state deregulation on commercial banks' efficiency within the US. We calculate an indicator of bank efficiency using Data Envelopment Analysis (DEA). The efficiency indicator is used as the primary step to analyze the effect of state branching law deregulation on bank's efficiency. The analysis is complemented with a failure prediction model using these DEA scores.