How often should suppliers be re-screened?

Point-in-time screening decays from the day it is run. OFAC amends the SDN List several times a month, and ownership, directorships, insolvency status and enforcement history all change without notifying you. A defensible cadence is risk-based rather than uniform: continuous or event-driven monitoring for high-risk and business-critical suppliers; a scheduled periodic refresh for the standard population; and trigger-based re-screening on contract renewal, expansion of scope, change of ownership or control, adverse media, or a change in the jurisdiction risk attaching to the supplier. Keep the evidence of every re-screen, including the ones that returned nothing - a screen you cannot produce on request is, for audit purposes, a screen you did not perform.