As part of their community action plans, the Allies Against Asthma coalitions have developed efforts to improve quality of care and promote health care system change. All the coalitions have used an interdisciplinary collaborative approach to design these strategies and demonstrated a range of intervention approaches appropriate to their local context and circumstances. The coalitions' collective experience suggests that coalitions provide three key forces for quality improvement and change that may be lacking in the current fragmented U.S. health care system--motivation to change the status quo, integration across systems, and accountability for results. The collaborative and empowering processes that a coalition model encourages and the direct advocacy opportunity provided to the consumer appear to bring these forces into play.