Implementation Guide: Transitioning from NIST SP 800-63-3 to SP 800-63-4

This implementation guide helps federal agencies transition from NIST SP 800-63-3 to NIST SP 800-63-4 by adopting a modern, risk-based approach to digital identity management. It explains the Digital Identity Risk Management (DIRM) framework and provides practical guidance for implementing updated Identity Assurance Levels (IAL), Authenticator Assurance Levels (AAL), and Federation Assurance Levels (FAL). The guide also addresses phishing-resistant authentication, identity proofing, AI governance, privacy, customer experience, redress processes, continuous monitoring, and performance metrics to help agencies modernize identity, credential, and access management while meeting evolving federal cybersecurity requirements.