Increasingly, IAM has become a tool not just for security but also for business agility. As firms exploit digital technologies to create new sources of value for customers and to increase their operational agility, vital business processes will invariably traverse different user populations, hosting models, and devices. These trends create pressing provisioning, authentication, and authorization challenges for S&R pros while security threats continue to swell. This report explains how S&R pros can apply our Zero Trust information security model to IAM to unify and improve access control across the business. This is an update of a previously published report; Forrester reviews and updates it periodically for continued relevance and accuracy.