Accept only external authenticators that are NIST-compliant; and Document and maintain a list of accepted external authenticators.

Acceptance of only NIST-compliant external authenticators applies to organizational systems that are accessible to the public (e.g., public-facing websites). External authenticators are issued by nonfederal government entities and are compliant with [SP 800-63B](#e59c5a7c-8b1f-49ca-8de0-6ee0882180ce) . Approved external authenticators meet or exceed the minimum Federal Government-wide technical, security, privacy, and organizational maturity requirements. Meeting or exceeding Federal requirements allows Federal Government relying parties to trust external authenticators in connection with an authentication transaction at a specified authenticator assurance level.