Dear Assurance Program Participants, This notice <https://kantarainitiative.org/publication-notice-sp-800-63b-4-service-assessment-criteria-sac/> confirms the formal publication of the Kantara Initiative International Assurance Program: SP 800-63B-4 Service Assessment Criteria (SAC) & Statement of Criteria Applicability (SoCA), aligned to NIST SP 800-63B Revision 4 – Authentication and Authenticator Management. Following completion of the public review process and consideration of community feedback, the assessment criteria have been finalized and are effective immediately. As of the publication date: - Authenticator Assurance Level (AAL) assessments can now be conducted against SP 800-63B-4. - Initial applications should be submitted to secretariat@kantarainitiative.org. - All organizations seeking assessment and certification are now required to contract directly with Kantara Initiative. Kantara will manage the engagement and assignment of accredited assessors. - The previous SP 800-63B-3 assessment criteria will continue to be available to those requiring it. - Trust Mark holders and registered applicants seeking certification are encouraged, but not required, to transition to SP 800-63B-4 upon renewal. The assessment documentation and supporting materials are provided with this notice and are also available through the Kantara Initiative website <https://kantarainitiative.org/download-category/service-assessment-criteria-sets/>. *Please note* that all <https://kantarainitiative.org/download-category/supporting-templates-service-provider-approval/>additional documentation <https://kantarainitiative.org/download-category/supporting-templates-service-provider-approval/> has also been updated – including the Application, Service Description, and Assessor Report. Kantara Initiative also advises that an updated SP 800-63 Revision 4 base publication package is currently in development. This forthcoming release will incorporate the Common Operational (CO_SAC) assessment criteria to support a unified Revision 4 assessment framework. Further details regarding publication timing and transition guidance will be provided separately. Questions regarding implementation or transition may be directed to the Assurance Program team at secretariat@kantarainitiative.org. *Lynzie Adams | **Assurance Program Manager* *Phone:* (301) 810-3977 *LinkedIn:* @KantaraInitiative *Sign up to receive our newsletter! <https://kantarainitiative.org/newsletter-form/>*