Each day, news reports cite instances of older adults across the United States being abused, denied needed care, or financially exploited, often by those they depend on. This report contains information on (1) existing estimates of the extent of elder abuse and their quality, (2) factors associated with elder abuse and its impact on victims, (3) characteristics and challenges of state Adult Protective Services (APS) responsible for addressing elder abuse, and (4) federal support and leadership in this area. To obtain this information, GAO reviewed relevant research; visited six states and surveyed state APS programs; analyzed budgetary and other federal documents; reviewed federal laws and regulations; and interviewed federal officials, researchers, and elder abuse experts. The most recent study of the extent of elder abuse estimated that 14.1 percent of noninstitutionalized older adults had experienced physical, psychological, or sexual abuse; neglect; or financial exploitation in the past year. This study and three other key studies GAO identified likely underestimate the full extent of elder abuse, however. Most did not ask about all types of abuse or include all types of older adults living in the community, such as those with cognitive impairments. In addition, studies in this area cannot be used to track changes in extent over time because they have not measured elder abuse consistently. Based on existing research, various factors appear to place older adults at greater risk of abuse. Physical and cognitive impairments, mental problems, and low social support among victims have been associated with an increased likelihood of elder abuse. Elder abuse has also been associated with negative effects on victims’ health and longevity. Although state APS programs vary in their organization and eligibility criteria, they face many of the same challenges. According to program officials, elder abuse caseloads are growing nationwide and cases are increasingly complex and difficult to resolve. However, according to GAO’s survey, APS program resources are not keeping pace with these changes. As a result, program officials noted that it is difficult to maintain adequate staffing levels and training. In addition, states indicated they have limited access to information on interventions and practices on how to resolve elder abuse cases, and may struggle to respond to abuse cases appropriately. Many APS programs also face challenges in collecting, maintaining, and reporting statewide case-level administrative data, thereby hampering their ability to track outcomes and assess the effectiveness of services provided. Federal elder justice activities have addressed some APS challenges, but leadership in this area is lacking. Seven agencies within the Departments of Health and Human Services (HHS) and Justice devoted a total of $11.9 million in grants for elder justice activities in fiscal year 2009. These activities have promoted collaboration among APS and its partners, such as law enforcement, but have not offered APS the support it says it needs for resolving elder abuse cases and standardizing the information it reports. Although the Older Americans Act of 1965 has called attention to the importance of federal leadership in the elder justice area, no national policy priorities currently exist. The Administration on Aging in HHS is charged with providing such leadership, but its efforts to do so have been limited. The Elder Justice Act of 2009 authorizes grants to states for their APS programs and provides a vehicle for establishing and implementing national priorities in this area, but does not address national elder abuse incidence studies. The Secretary of HHS should determine the feasibility of providing APS-dedicated guidance, and, in coordination with the Attorney General, facilitate the development and implementation of a nationwide APS data system. Also, Congress should consider requiring HHS to conduct a periodic study to estimate elder abuse’s extent. HHS indicated that it will review options for implementing GAO’s recommendations.