In a new Commonwealth Fund issue brief, health law and policy expert Sara Rosenbaum and her team at George Washington University analyze the choices being made by the group of states that, together with the District of Columbia, have already begun establishing health insurance exchanges, either through legislation or executive order. While the study reveals a great deal of variation in approach, it also shows a common tendency to accord exchanges considerable flexibility in how they will operate and what standards they will apply to the insurance products sold. Also available is an interactive map displaying state activity on health insurance exchanges.