GAO's survey of IHS and tribally operated hospitals found that these hospitals' ability to collect and preserve medical forensic evidence in cases of sexual assault and domestic violence varies from hospital to hospital; of the 45 hospitals, 26 reported that they are typically able to perform medical forensic exams on site for victims of sexual assault; 19 reported that they choose to refer sexual assault victims to other facilities. GAO found that the utility of medical forensic evidence in any subsequent criminal prosecution depends on hospital staff's properly preserving an evidentiary chain of custody, which depends largely on coordination with law enforcement agencies. IHS has made significant progress since 2010 in developing required policies and procedures on medical forensic services for victims of sexual assault; nevertheless, challenges in standardizing and maintaining such services remain. In March 2011, IHS took a first step in an ongoing effort to standardize medical forensic services by issuing its first agency-wide policy on how hospitals should respond to adult and adolescent victims of sexual assault. Remaining challenges include systemic issues, such as overcoming long travel distances between Indian reservations or Alaska Native villages and IHS or tribal hospitals. GAO offers five recommendations intended to improve IHS's response to sexual assault and domestic violence, including the development, implementation, and monitoring plan for its new sexual assault policy. 1 table and 8 figures