While the addition of many cardiology codes to the ASC Covered Procedures List over the past three years may seem sudden to some, this move is more than 15 years in the making. It began with the Medicare Prescription Drug, Improvement, and Modernization Act (MMA) of 2003, which directed the US Department of Health & Human Services (HHS) secretary to implement a revised payment system for surgical services furnished in ASCs. Although work related to ASC payments was going on for years before the MMA was adopted, that law served as the catalyst for the payment system ASCs have today.