The Cognitive Event RElated Biometric REcognition (CEREBRE) protocol recently achieved a significant benchmark in brain biometrics: namely, it was demonstrated to provide 100% identification accuracy in a pool of 50 participants. One clear question regarding this result is whether it is stable over time. Functional brain organization, of course, is constantly changing, with new memories being added and new associations being formed daily. Thus, it is reasonable to ask whether a biometric protocol based on functional brain organization– which CEREBRE is– will provide stable identification over time. Here we asked 20 participants to provide CEREBRE reference data and then return between 48 and 516 days later to challenge the system. Results indicate that even at 516 days after the initial reference was acquired the CEREBRE protocol still provides 100% identification accuracy in this pool of users. These data provide strong evidence that the biometric permanence of the CEREBRE protocol is at least stable across the 516 day inter-session lag.