The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) established a new framework for Medicare physician payment. Designed to stabilize uncertain payment rates for Medicare’s fee-for-service (FFS) system and incentivize physicians to move into new alternative payment systems, MACRA contains several uncertainties of its own. In a textbook illustration of why it’s important to be careful what you wish for, it’s increasingly easy to predict that implementation of MACRA will be delayed as a result of both regulatory and legislative breaches of its statutory timeline. This article traces the contemporary history of the Medicare physician payment system and efforts to implement additional changes.