The authority chain for every IRC section.

Explore statute text, Treasury regulations, and citing cases — with verified context wherever the source text supports it.

10,682

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25,831

Tax Court cases

34,671

Regulations

540,984

Citation edges

4,451

Federal cases

From the graph

Most-cited sections

§1 9,030 cites
§6662(a) 4,606 cites
§301 3,587 cites
§6651(a) 3,368 cites
§7491(a) 3,314 cites

Most followed

Still standing

Decided in 2013:
Alfred Q. Campbell, III, Petitioner
3 cases have followed it

Highest followed rate