What is the difference between U.S.C., U.S.C.A., and U.S.C.S.?

U.S.C. is the official United States Code published by the U.S. Government Publishing Office. U.S.C.A. (United States Code Annotated) is the unofficial version published by West and includes annotations summarizing court decisions interpreting each provision. U.S.C.S. (United States Code Service) is the LexisNexis-published version, also with annotations. Bluebook prefers U.S.C. as the official source. Cite U.S.C.A. or U.S.C.S. only when the provision has not yet appeared in the official U.S.C., which is typical for very recent amendments.

Do I need to include the year when citing a statute?

Yes. The year in parentheses is mandatory under Bluebook Rule 12.3.2. It refers to the edition of the code you are citing, not the year the statute was enacted. The current main edition of the U.S. Code is 2018, with annual supplements for later amendments. If you are citing a provision that was added or amended after the main edition, cite the appropriate supplement: e.g., 42 U.S.C. § 1983 (Supp. II 2020).

How do I cite a statute that is known by its popular name?

For well-known statutes, you can cite by popular name at first reference. The format typically includes the popular name, the public law number, the session law citation, and a parenthetical explaining where the statute is codified. For example: "Civil Rights Act of 1964, Pub. L. No. 88-352, 78 Stat. 241 (codified as amended at 42 U.S.C. §§ 2000a to 2000h-6 (2018))." Subsequent references can use a shortened form like "Civil Rights Act, 42 U.S.C. § 2000e-2."

How do I cite a constitutional provision in Bluebook?

Constitutional provisions follow a simpler format than statutes. The citation begins with "U.S. Const." followed by "art." (article) or "amend." (amendment), the article or amendment number in Roman numerals, and any section or clause designation. Examples: "U.S. Const. art. I, § 8, cl. 3" (the Commerce Clause) or "U.S. Const. amend. XIV, § 1" (Section 1 of the Fourteenth Amendment). Constitutional citations do not include a year. For state constitutions, substitute the state abbreviation: "Cal. Const. art. I, § 7."

How to Cite a Federal Statute in Bluebook Format

Q: What is a session law and when should I cite it?

Session laws are the acts of Congress as originally passed, published in the Statutes at Large ("Stat."). Cite session laws when (1) the statute has not yet been codified in the U.S. Code, (2) you are specifically referring to the historical version as enacted (such as for legislative history analysis), or (3) the statute has been repealed but you need to discuss it. For statutes currently in force and codified in the U.S. Code, cite the U.S.C. instead.

Federal statutes are the backbone of American law, and citing them correctly in Bluebook format is a core skill every law student and practicing attorney needs. Whether you are citing 42 U.S.C. § 1983 in a civil rights complaint, the Americans with Disabilities Act in a compliance memo, or a newly enacted public law in a current-events piece, The Bluebook: A Uniform System of Citation (21st edition) governs statute citations in Rule 12. Getting the title, section symbol, code, and year right the first time saves hours of editor cleanup later.

If you want to skip the manual formatting and generate a statute citation directly, you can use the AllCitations Bluebook generator to format any federal or state statute in seconds. But understanding Rule 12 is essential for citing session laws, knowing when to include the year, and handling statutes that go by their popular names rather than section numbers.

The Official Rule (Bluebook Rule 12)

Bluebook Rule 12 governs citations to statutes, including the U.S. Code, session laws, state codes, and constitutional provisions. For a federal statute currently in force and published in the United States Code, the standard format is:

Title U.S.C. § Section (Year).

Applied to a real statute:

42 U.S.C. § 1983 (2018).

Each element follows specific rules:

Title is the title number in the United States Code. The U.S. Code is organized into 54 titles covering different subject areas (Title 42 is public health and welfare; Title 18 is crimes and criminal procedure; Title 26 is internal revenue).
U.S.C. is the standard abbreviation for United States Code, the official compilation of federal laws. Use "U.S.C." for the official code, "U.S.C.A." for the unofficial West-published United States Code Annotated, and "U.S.C.S." for the LexisNexis-published United States Code Service.
§ is the section symbol. For multiple sections, use "§§" (two section symbols).
Section is the specific section number. Section numbers often include subsections separated by parentheses or letters (e.g., § 1983(a)).
Year appears in parentheses at the end. For the U.S.C., the year is the year of the code edition you are citing. The current U.S.C. edition is 2018, with supplements for later years.

The U.S.C., U.S.C.A., and U.S.C.S.

There are three versions of the United States Code, each with different publishers and slightly different purposes. Bluebook Rule 12.3 establishes a preference order:

U.S.C. is the official United States Code published by the U.S. Government Publishing Office. This is the preferred source and should be cited whenever the provision you are referencing has been published in it. New editions of the official U.S.C. are published every six years, with annual supplements in between.
U.S.C.A. is the United States Code Annotated, published by West (now Thomson Reuters). It includes annotations summarizing court decisions interpreting each provision. Cite U.S.C.A. only when the provision has not yet appeared in the official U.S.C., typically for very recent amendments.
U.S.C.S. is the United States Code Service, published by LexisNexis. Like U.S.C.A., it includes annotations. Cite U.S.C.S. only when neither U.S.C. nor U.S.C.A. is available.

In practice, most citations use U.S.C. because the official code covers the vast majority of federal law in force. Cite U.S.C.A. or U.S.C.S. only for statutes that have been amended in the current year and are not yet in the official supplement.

Worked Examples

Below are six worked examples covering the most common federal statute citation scenarios.

1. A Standard Section Citation

The most common case: a single section of the U.S. Code.

42 U.S.C. § 1983 (2018).

This cites Section 1983 of Title 42 of the United States Code, 2018 edition. Section 1983 is the civil rights cause of action for constitutional violations by state actors.

2. Multiple Sections

When citing more than one section in the same title, use "§§" (double section symbol) and separate sections with commas or ranges.

42 U.S.C. §§ 2000e-2, 2000e-3 (2018).

42 U.S.C. §§ 12101-12213 (2018).

The first example cites two specific sections of Title VII of the Civil Rights Act. The second example cites a range covering the Americans with Disabilities Act.

3. A Subsection

For subsections, include the subsection letter or number in parentheses immediately after the main section number.

42 U.S.C. § 1983(a) (2018).

26 U.S.C. § 501(c)(3) (2018).

The second example is the famous tax code provision for nonprofit organizations, with two levels of subsection (c) and (3).

4. A Session Law Citation

When a statute has been enacted too recently to appear in the U.S. Code, or when you want to cite the statute as originally enacted (with its popular name), cite the session law instead. Session laws appear in the Statutes at Large ("Stat.").

Affordable Care Act, Pub. L. No. 111-148, 124 Stat. 119 (2010) (codified as amended in scattered sections of 26 and 42 U.S.C.).

Here "Pub. L. No. 111-148" is the public law number (the 148th public law of the 111th Congress), 124 is the volume of Statutes at Large, and 119 is the first page. The parenthetical at the end explains where the law is now codified.

5. A Statute by Popular Name

Some statutes are best known by their popular names. Bluebook allows citing by popular name for certain well-known acts, especially at first reference.

Civil Rights Act of 1964, Pub. L. No. 88-352, 78 Stat. 241 (codified as amended at 42 U.S.C. §§ 2000a to 2000h-6 (2018)).

This cites the Civil Rights Act by its popular name, includes its public law and session law citation, and explains where it is currently codified.

6. A Constitutional Provision

Constitutional provisions follow a simpler format: jurisdiction, abbreviation, article or amendment, and section or clause.

U.S. Const. art. I, § 8, cl. 3.

U.S. Const. amend. XIV, § 1.

The first is the Commerce Clause. The second is Section 1 of the Fourteenth Amendment (due process, equal protection, privileges and immunities). Note that "art." is lowercase for article, "amend." is lowercase for amendment, and "cl." is lowercase for clause.

Pin Cites for Statutes

Unlike cases, statutes don't have pin cites in the same sense. The section number already points readers to the specific provision you're citing. If you need to refer to a specific subsection, include it in parentheses:

42 U.S.C. § 1983(a) (2018).

26 U.S.C. § 501(c)(3)(A) (2018).

When quoting statutory language, include the section number in the citation and place the quotation in text with proper attribution.

When to Include the Year

The year in parentheses refers to the edition of the United States Code you are citing. The official U.S.C. is published in new editions every six years (e.g., 2006, 2012, 2018, 2024), with annual supplements in between. Current Bluebook practice is:

Cite the most recent main edition of the U.S.C. that contains the provision (as of this writing, the 2018 edition or the 2024 edition, depending on publication status).
For provisions added or amended after the most recent main edition, cite the appropriate supplement: 42 U.S.C. § 1983 (Supp. II 2020).
For session laws and public laws, the year is the year of enactment, not the year of the code edition.

The year is not optional. Omitting it is a Bluebook error under Rule 12.3.2.

Common Mistakes and How to Avoid Them

Using "Section" instead of the section symbol (§). Bluebook requires the § symbol (or §§ for multiple sections) in citations. Writing "42 U.S.C. Section 1983 (2018)" is incorrect. The § symbol is standard and should be used in citations, though "Section" (capitalized) can appear in textual sentences.

Confusing U.S.C., U.S.C.A., and U.S.C.S. These are three different publications. Always cite U.S.C. (the official code) when possible. Cite U.S.C.A. or U.S.C.S. only when the provision has not yet appeared in the official code, typically for very recent amendments.

Omitting the year. The year in parentheses is mandatory. The U.S. Code is updated regularly, and the year tells readers which edition you consulted. Omitting it is a common student error.

Wrong spacing around the section symbol. There should be a non-breaking space between § and the section number: "§ 1983", not "§1983". When using double section symbols, the spacing is "§§ 2000e-2", not "§§2000e-2".

Citing a session law when the statute is codified. If a statute has been codified in the U.S. Code, cite the code (e.g., 42 U.S.C. § 1983 (2018)), not the session law. Cite session laws only when the statute has not yet been codified or when you are specifically referring to the historical version as enacted.

Missing subsection letters or numbers. Subsections are part of the section number and must be included in the citation: 26 U.S.C. § 501(c)(3), not 26 U.S.C. § 501 (2018) when you are actually citing subsection (c)(3).

Using "et seq." casually. "Et seq." means "and following" and is used in legal writing to refer to a section and those that follow. Bluebook generally prefers you cite the specific sections rather than using "et seq.", but it can be appropriate for broad references to an entire act. Do not use it when a specific range of sections would be more precise.

Incorrect range format for multiple sections. When citing a range, use "§§" and a hyphen: "42 U.S.C. §§ 12101-12213". Do not write "§§ 12101 to 12213" unless the sections are not consecutively numbered.

Quick-Reference Table

Scenario	Format	Example
Single section	Title U.S.C. § Section (Year)	42 U.S.C. § 1983 (2018)
Multiple sections	Title U.S.C. §§ Section, Section (Year)	42 U.S.C. §§ 2000e-2, 2000e-3 (2018)
Section range	Title U.S.C. §§ First-Last (Year)	42 U.S.C. §§ 12101-12213 (2018)
Subsection	Title U.S.C. § Section(letter) (Year)	26 U.S.C. § 501(c)(3) (2018)
Session law	Pub. L. No. X-X, Vol Stat. Page (Year)	Pub. L. No. 111-148, 124 Stat. 119 (2010)
Statute by popular name	Popular Name, Pub. L. details (codified at Title U.S.C.)	Civil Rights Act of 1964, Pub. L. No. 88-352, 78 Stat. 241
Constitutional provision	U.S. Const. art./amend. #, § #, cl. #	U.S. Const. amend. XIV, § 1

Tools and Resources

AllCitations Bluebook Generator: Enter a statute and get a correctly formatted Bluebook citation, including title, section, and year.
Cornell Legal Information Institute U.S. Code: Free, searchable access to the complete United States Code. Use this to verify section numbers and confirm the current version of any provision.
Congress.gov: The official source for federal legislation, including bills, public laws, and session laws. Use this to find public law numbers and Statutes at Large citations.

For guidance on citing cases alongside statutes in your footnotes, see our guide to How to Cite a Supreme Court Case in Bluebook Format.