NIST SP 800-178 October 2016 Extensible Access Control Markup Language (XACML) and Next Generation Access Control (NGAC) are very different attribute based access control (ABAC) standards with similar goals and objectives. An objective of both is to provide a standardized way for expressing and enforcing vastly diverse access control policies on various types of data services. However, the two standards differ with respect to the manner in which access control policies are specified and implemented. This document describes XACML and NGAC, and then compares them with respect to five criteria. The goal of this publication is to help ABAC users and vendors make informed decisions when addressing future data service policy enforcement requirements. Why buy an eBook when you can download a PDF for free? First you gotta find it and make sure it’s the latest version, not always easy. It’s much more cost-effective to just order the latest version from Amazon.com Unlike a PDF, this eBook allows easy page navigation because we bookmarked the Chapters and Appendices. (Don’t judge based on the free sample because that functionality is not activated on the free sample.) Once you buy a copy you will see how easy it is to get to the information you seek - fast. This material is published by 4th Watch Publishing Co. We publish tightly-bound, full-size books at 8 ½ by 11 inches, with glossy covers. 4th Watch Publishing Co. is a Service Disabled Veteran Owned Small Business (SDVOSB) and is not affiliated with the National Institute of Standards and Technology. A full copy of over 300 cybersecurity standards is loaded on our CyberSecurity Standards Library DVD which is available at Amazon.com. And, if you need to look up an acronym or the definition of a word, just go to the Cyber Dictionary.