---
kind: "unit"
title: "26"
title_heading: "Internal Revenue"
key: "chI"
level: "chapter"
label: "Chapter I"
heading: "Internal Revenue Service, Department of the Treasury"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/26/chI"
sections_count: 6156
---

# Chapter I — Internal Revenue Service, Department of the Treasury

Title 26 C.F.R. — Internal Revenue

## Contents

- [Subchapter A — Income Tax](/cfr/26/chI-subchA.md)
- [Subchapter B — Estate and Gift Taxes](/cfr/26/chI-subchB.md)
- [Subchapter C — Employment Taxes and Collection of Income Tax at Source](/cfr/26/chI-subchC.md)
- [Subchapter D — Miscellaneous Excise Taxes](/cfr/26/chI-subchD.md)
- [Subchapter E — Subchapter E [reserved]](/cfr/26/chI-subchE.md)
- [Part 170-299 — Parts 170-299 [reserved]](/cfr/26/chI-part170-299.md)
- [Subchapter F — Procedure and Administration](/cfr/26/chI-subchF.md)
- [Subchapter G — Regulations under Tax Conventions](/cfr/26/chI-subchG.md)
- [Subchapter H — Internal Revenue Practice](/cfr/26/chI-subchH.md)