From the Cybersecurity & Infrastructure Security Agency, the K-12 School Security Guide (3rd ed., 2022) provides a comprehensive doctrine and systems-based methodology to support schools in conducting vulnerability assessments and planning to implement layered physical security elements across K–12 districts and campuses. The primary focus will be on protection and mitigation measures and strategies schools should consider in their broader school safety enterprise. The guide is designed and organized for local education agencies to employ in conjunction with the K-12 School Security Assessment Tool (SSAT), a web-based tool that provides further guidance on school physical security planning and implementation. Together, this guide and the companion tool outline action-oriented security practices and options for consideration across the K-12 school community.