Federal agencies have led the development of adaptation principles and tools in forest ecosystems over the past decade. Successful adaptation efforts generally require organizations to: (1) develop science-management partnerships, (2) provide education on climate change science, (3) provide a toolkit of methods and processes for vulnerability assessment and adaptation, (4) use multiple models to generate projections of climate change effects, (5) incorporate risk and uncertainty, (6) integrate with multiple management objectives, (7) prioritize no-regrets decision making, (8) support flexibility and adaptive learning, and (9) incorporate adaptation in planning and projects. Resistance, resilience, response, and realignment strategies help to identify the scope of appropriate adaptation options at broad spatial scales in forest ecosystems. At the local scale, it is necessary to: (1) define management objectives, spatial extent, and timeframes, (2) analyze vulnerabilities, (3) determine priorities, (4) develop local tactics associated with strategies, (5) implement plans and projects, and (6) monitor, review, and adjust. The best examples of vulnerability assessment and adaptation planning in forests have occurred in national forests, where science-management partnerships have been established across multiple institutions. Although strategic planning for adaptation has been increasing, implementation of on-the-ground adaptation projects has been rare, primarily because of a lack of budget, personnel, and mandate for action. No one agency or organization can fully meet the challenge of adaptation, but this task is within reach if willing partners work collaboratively toward sustainable management grounded in knowledge of climate science and dynamic ecosystems.