HHS has declared that the “warning period” for information blocking is over, putting HIEs, HINs, developers, and providers squarely in the path of active enforcement. With OIG empowered to levy million-dollar penalties, ONC able to strip certifications, and CMS now finalizing monetary disincentives for certain providers, the consequences are real and far-reaching. At the same time, long-standing practices, such as conservative privacy policies or restrictive BAAs, may suddenly collide with federal interoperability mandates. This article examines the new enforcement posture, the risks and dilemmas it creates, and what health information networks and their provider members must do to prepare.