In summary, the appendix of NIST Special Publication 800-53 provides a two-way mapping between the security controls of NIST and ISO/IEC. The document also maps these controls to the Cybersecurity Framework core, which is widely used in the industry. Additionally, a mapping from NIST to ISO/IEC controls can be found in Appendix H. When deciding between NIST 800-53, ISO 27002, or NIST CSF for an IT security program, it is important to understand the differences between them. This document also provides a mapping between the controls in NIST Special Publication 800-53 and ISO/IEC 27001:2013, making it easier to implement a comprehensive security program.