Value-based payment (VBP) arrangements (also known as outcomes- or performance-based contracting) for drugs transform drug pricing from paying for expected benefits projected from clinical trials to paying for actual benefits received by patients. But despite enthusiasm for new payment approaches, a new CMS rule could complicate implementation and impact patient access. Mark R. Trusheim, Brian Sils, Casey Quinn, and Michael Ciarametaro discuss in this new blog post on Health Affairs.