In his research, Dr. Carr initially focused on high-acuity care, but found that the full breadth of emergency care also includes lower-acuity care. As the health care delivery system has evolved, emergency medicine—including urgent care and telemedicine—has emerged as a key home for unscheduled acute care. Integrating emergency care into this broader health care delivery system has launched new research portfolios focused on understanding the association between unscheduled care and population health, how payment and regulatory functions influence care utilization and outcomes, and how delivery system innovations can make health care more timely, efficient, and patient-centered.