The WTC Health Program provides health care services to eligible responders and survivors of the September 11, 2001, attacks through eight clinics. NIOSH and clinics share responsibility for several program components. The James Zadroga 9/11 Health and Compensation Reauthorization Act, which extended the program to 2090, included a provision for GAO to examine three of these components--certification of conditions for treatment coverage, actions to ensure appropriate payments, and quality assurance. This report examines (1) the development and implementation of policies, procedures, and guidance for certifying health conditions, (2) actions taken to ensure appropriate payments, and (3) the development and implementation of a quality assurance program, including mandated elements. GAO reviewed relevant legal requirements, policies and procedures, and clinic contracts. GAO also interviewed NIOSH officials, clinics, and responder and survivor committees.