6 CFR 27.220: Tiering.

(a) Preliminary determination of risk-based tiering. Based on the information the Department receives in accordance with §§ 27.200 and 27.205 (including information submitted through the Top-Screen process) and following its initial determination in § 27.205(a) that a facility presents a high level of security risk, the Department shall notify a facility of the Department's preliminary determination of the facility's placement in a risk-based tier.

(b) Confirmation or alteration of risk-based tiering. Following review of a covered facility's Security Vulnerability Assessment, the Executive Assistant Director shall notify the covered facility of its final placement within a risk-based tier, or for covered facilities previously notified of a preliminary tiering, confirm or alter such tiering.

(c) The Department shall place covered facilities in one of four risk-based tiers, ranging from highest risk facilities in Tier 1 to lowest risk facilities in Tier 4.

(d) The Executive Assistant Director may provide the facility with guidance regarding the risk-based performance standards and any other necessary guidance materials applicable to its assigned tier.