For · tax
Title 26 is two books, and the answer is usually in the third.
The Code is one corpus, the regulations under it are another, and the thing a practitioner actually reaches for — a revenue procedure, a notice, the Manual section a revenue agent is working from — is a third. All three are citable, all three move, and a position taken in 2021 has to be defended against the 2021 text.
“What does the Code itself say gross income is?”
corpus=statutes · citation=26-61 → 26 U.S.C. § 61
“And the regulation under it?”
corpus=regulations · citation=26-1.61-1 → 26 C.F.R. § 1.61-1
“What did that regulation say when the return was filed?”
add asOf=2021-04-15 — act-effective-date validity, so the window is the real one
“Is there a revenue procedure on this?”
corpus=guidance · rev-proc-2026-17 — built and scheduled weekly, not yet served
What it takes
The corpora this runs on, named.
Statutes
1,946,798
read 2026-09-26
Regulations
1,066,551
read 2026-09-26
Agency guidance
20,436
read 2026-09-20
The statute and the regulation under it are one key apart — 26-61 in statutes, 26-1.61-1 in regulations — and the procedural regulations live in the same place (26-601.201, rulings and determination letters). The whole Code of Federal Regulations is carried, so Title 26 is not a special case that needed a bespoke pipeline; it refreshes on the same monthly cycle as every other title.
Regulations carry act-effective-date validity, which is the strongest of the four temporal bases: the window came from the amendment itself, not from when a publisher reprinted the volume. For a tax position that is the difference between a defensible lookback and a guess.
Worked
Real calls, real records.
(a) General definition — Except as otherwise provided in this subtitle, gross income means all income from whatever source derived…
- citation.display
- 26 U.S.C. § 61
- catchline
- Gross income defined
- status
- active
- provenance.sourceSystem
- uscode.house.gov
- provenance.contentHash
- 400a91b2931fcebdf3cdbfc6514ceff83b9faf63e4917e3fe4dfc1cdbddda4d9
(a) General definition. Gross income means all income from whatever source derived, unless excluded by law.
- citation.display
- 26 C.F.R. § 1.61-1
- catchline
- Gross income
- validFrom → validTo
- 2016-07-26 → present
- temporalBasis
- act-effective-date
- provenance.sourceSystem
- ecfr.gov
- provenance.retrievedAt
- 2026-07-22
The statute and the regulation under it are one key apart: 26-61 in statutes, 26-1.61-1 in regulations. Same call, same provenance contract.
check this record →What this does not do
The Internal Revenue Bulletin and the Internal Revenue Manual are the two pieces this practice needs most and they are not in the served corpus yet. Both are written: the Bulletin is keyed rev-rul-2026-7, rev-proc-2026-17, notice-2026-19, ann-2026-16, and it refreshes weekly rather than monthly because a Bulletin issue carries new guidance that did not exist the week before. The Manual is keyed irm-4.10.3.4.7.1, with each subsection dated by its own revision stamp, and is loaded a part at a time.
Neither will be advertised as coverage until the coverage endpoint reports it. Private letter rulings, technical advice memoranda and chief counsel advice are not attempted at all.