This report examines the extent, causes, and consequences of instability in public coverage programs for children and families. It focuses particularly on the phenomenon of "churning," which occurs when individuals lose and regain coverage in a short period of time. It also looks at strategies to make public program coverage more stable for children and families. Findings are drawn from a variety of sources, including national and state-based studies, roundtable discussions and interviews with stakeholders and experts, and an examination of the affect of state and local policies on instability and churning in four states: Louisiana, Rhode Island, Virginia, and Washington. The experiences of these states demonstrate that coverage instability can be averted to a significant degree by adopting key policies and procedures, like limiting the frequency of required renewals; developing easy, seamless transitions among public coverage programs; and setting affordable limits on premium costs.