During the transition to new health insurance marketplaces, insurers revamped their approach to network design, and many now offer narrower provider networks. Researchers assessed network changes and efforts at regulatory oversight in six states. Researchers found that insurers made significant changes to the networks of their individual market plans. Insurers and state officials reported confusion about which plan networks included which providers, but most received few complaints about consumers' ability to obtain in-network services. While half these states have taken action to improve provider directories, it appears unlikely that states will dramatically change network standards, at least in the short-term.