Key Takeaways

  • The IRC is Title 26 of the United States Code.
  • Code sections are the primary reference point (e.g., §162 Business Expenses).
  • Flush language is unnumbered text within a code section that modifies preceding paragraphs.
  • Congress enacts tax law; the President signs it.
  • Key subtitles: A (Income), B (Estate/Gift), C (Employment), F (Procedure).
  • The Code defines what is taxable; regulations explain how to apply it.
Last updated: January 2026

Internal Revenue Code (Title 26): The Foundation of Tax Law

Why This Matters for the Exam

The Internal Revenue Code is the starting point for every tax question. Part 3 tests your understanding of how the Code is organized, how to read citations, and the relationship between the Code and other authorities.

Understanding the Code's structure helps you navigate tax research and recognize when other authorities (regulations, rulings) are interpreting vs. contradicting the statute.

Expect at least 1-3 questions on the Code's structure and the legislative process.

What Is the Internal Revenue Code?

The Internal Revenue Code (IRC) is Title 26 of the United States Code. It is the primary source of federal tax law in the United States.

Key Facts:

  • Enacted by Congress (legislative branch).
  • Signed into law by the President (executive branch).
  • Interpreted by the IRS and Treasury (administrative authorities).
  • Adjudicated by federal courts (judicial branch).

Structure of the Code

The IRC is organized hierarchically:

LevelExampleDescription
TitleTitle 26The entire Internal Revenue Code
SubtitleSubtitle AIncome Taxes
ChapterChapter 1Normal Taxes and Surtaxes
SubchapterSubchapter BComputation of Taxable Income
PartPart VIItemized Deductions
Section (§)§162Trade or Business Expenses
Subsection§162(a)General rule
Paragraph§162(a)(1)First paragraph
Subparagraph§162(a)(1)(A)Subparagraph A
Clause§162(a)(1)(A)(i)Clause i

Major Subtitles

SubtitleTitleKey Content
AIncome TaxesIndividual and corporate income tax (§1-§1400Z)
BEstate and Gift TaxesTransfer taxes at death or gift (§2001-§2704)
CEmployment TaxesFICA, FUTA, withholding (§3101-§3510)
DMiscellaneous Excise TaxesExcise taxes on specific goods/activities
EAlcohol, Tobacco, and FirearmsSpecific excise taxes
FProcedure and AdministrationIRS procedures, penalties, statutes (§6001-§7874)

Exam Focus: Most Part 3 questions relate to Subtitle F (Procedure and Administration), which covers:

  • Information returns and record requirements.
  • Assessment and collection procedures.
  • Penalties (civil and criminal).
  • Statutes of limitations.
  • Judicial proceedings.

How to Read a Code Citation

Example: IRC §162(a)(1)

ComponentMeaning
IRCInternal Revenue Code
§162Section 162 (Trade or Business Expenses)
(a)Subsection (a) - "In general"
(1)Paragraph (1) - "a reasonable allowance for salaries..."

"Flush Language": Unnumbered text that appears after a list of paragraphs. It modifies or limits all preceding paragraphs. Watch for flush language—it often contains important exceptions or definitions.

The Legislative Process

StepActorWhat Happens
1House Ways & MeansTax bills originate in the House
2Full HouseVotes on the bill
3Senate FinanceReviews and amends the bill
4Full SenateVotes on the bill
5Conference CommitteeReconciles House/Senate versions
6Both ChambersVote on final version
7PresidentSigns into law (or vetoes)

Key Point: The IRS cannot create tax law. Only Congress can enact statutes. The Treasury can only interpret what Congress has enacted.

Common Code Sections to Know

SectionTopic
§61Gross Income Defined
§162Trade or Business Expenses
§179Election to Expense Certain Property
§263Capital Expenditures
§1031Like-Kind Exchanges
§1231Gains and Losses on Business Property
§6011Return Requirements
§6651Failure to File / Failure to Pay Penalties
§6662Accuracy-Related Penalty
§6694Understatement Preparer Penalties
§7206Fraud and False Statements

Real-World Scenario

Scenario: A client asks if they can deduct a particular expense. You research and find that §162 allows deductions for "ordinary and necessary" business expenses, but a Treasury Regulation limits the deduction in certain circumstances.

  • Question: Which authority controls?
  • Answer: The Code controls. If the regulation is consistent with §162, follow it. If the regulation contradicts or expands beyond §162, a court may invalidate it (especially post-Loper Bright).

On the Exam

Expect 1-3 questions on the IRC, typically:

  1. Structure Questions: "Which subtitle covers Procedure and Administration?"
  2. Citation Questions: "In §162(a)(1), what does '(a)' represent?"
  3. Legislative Questions: "Which branch enacts the Internal Revenue Code?"

The key is to remember: Title 26, Congress enacts, Subtitle F = Procedure, Section > Subsection > Paragraph.

Test Your Knowledge

Which branch of government enacts the Internal Revenue Code?

A
B
C
D
Test Your Knowledge

In the citation "IRC § 162(a)(1)", what does "(a)" represent?

A
B
C
D
Test Your Knowledge

Which subtitle of the IRC covers "Procedure and Administration"?

A
B
C
D