This guide covers an individual tax controversy from the first notice through collection resolution years later. Part 1 explains assessment and why it is the hinge of the entire system. Parts 2 and 3 cover examination and the Independent Office of Appeals. Part 4 covers the notice of deficiency and the ninety-day petition period. Part 5 covers refund litigation and the full payment rule. Parts 6 through 9 cover liens, levies, collection due process, and the collection alternatives. Parts 10 through 12 cover penalties and abatement, innocent spouse relief, and the limitation periods that govern everything. Part 13 covers the taxpayer rights that are operational rather than aspirational, and Part 14 sets out practice notes by role.