Agencies can enhance and sustain their collaborative efforts by engaging in eight practices: (1) define and articulate a common outcome; (2) establish mutually reinforcing or joint strategies; (3) identify and address needs by leveraging resources; (4) agree on roles and responsibilities; (5) establish compatible policies, procedures, and other means to operate across agency boundaries; (6) develop mechanisms to monitor, evaluate, and report on results; (7) reinforce agency accountability for collaborative efforts through agency plans and reports; and (8) reinforce individual accountability for collaborative efforts through performance management systems. Running throughout these practices are a number of factors, such as leadership, trust, and organizational culture that are necessary elements for a collaborative working relationship. Also, the Government Performance and Results Act (GPRA) provides a framework Congress, Office of Management and Budget (OMB), and executive branch agencies can use to consider the appropriate mix of long-term strategic goals and strategies needed to identify and address issues that cut across agency boundaries. In addition, it was also recommended that OMB develop a governmentwide performance plan as required by GPRA and that Congress consider amending GPRA to require a governmentwide strategic plan. The Government Accountability Office (GAO) recommends that OMB focus on additional programs in need of collaboration and promote the practices in this report. The Federal Government faces a series of challenges in the 21st century that will be difficult for any one single agency to address alone. To help agencies overcome the barriers, this report identifies key practices that can help enhance and sustain Federal agency collaboration, along with illustrative examples from select agencies.