This article provides an initial assessment of the Affordable Care Act's recent implementation experience in the states. Drawing on state-level and regional analyses that have been coordinated by the ACA Implementation Network – a cooperative effort involving researchers in 35 states – this article highlights the uncertain policy environment associated with the politics and complexities of the ACA. Understanding the ACA implementation experience requires an appreciation for political context, but must also take into account underlying demographic, market, and state administrative capacity issues in the states. There are indications that the ACA implementation experience is moving from a highly charged partisan nature to a more accommodating posture long associated with intergovernmental relations between the federal and state government in health and human services administration. in short, the key questions going forward will turn on how, not whether, the ACA is implemented.