The fiscal cliff debate culminated in the passage of the American Taxpayer Relief Act of 2012 (ATRA). ATRA makes permanent most of the tax cuts enacted in 2001 and 2003, permanently patches the alternative minimum tax, extends for five years the enhancements to individual income tax credits originally enacted in the 2009 stimulus legislation, and temporarily extends certain other tax provisions. This paper provides a detailed description of the individual, corporate, and estate tax provisions in ATRA.