As perhaps the broadest overhaul of the tax code in recent memory, the Tax Reform Act of 1986 (TRA86) often stands as a reference point in discussions of future tax reforms. Although this reform looms large in the imagination of many policymakers, tax reform discussions are often hampered by a limited understanding of what changes to the tax code actually took place in 1986. This primer outlines the major changes of TRA86, as well as the current state of the code, in order to promote a better understanding of that often-cited legislation.