APSA citation style is the author-date citation system published by the American Political Science Association in its Style Manual for Political Science. It pairs a short parenthetical citation, such as (Putnam 2000), with a full entry on a reference list, and it is the required format for most political science courses and journals. This guide covers the exact in-text and reference list rules, with examples for books, articles, websites, and government documents.
What Is APSA Citation Style?
The APSA Style Manual is the official guide political science departments use for formatting papers, in-text citations, and reference lists. APSA style is not a stand-alone invention. It is built on the author-date system from the Chicago Manual of Style, 17th edition, with a handful of discipline-specific adjustments for political science research, such as headline-style capitalization for titles and specific formats for legal and government sources.
Unlike Chicago, which offers writers a choice between notes-bibliography and author-date systems, APSA uses only the author-date system. Every source cited in the text is matched to a full entry in an alphabetized reference list at the end of the paper.
APSA vs. Chicago, APA, and MLA
Because APSA style borrows so much from Chicago, students often confuse the two, or assume APSA mirrors APA since both cite by name and year. The table below breaks down the practical differences.
| Style | How it differs from APSA |
|---|---|
| Chicago (author-date) | Nearly identical rules, but Chicago also allows a notes-bibliography option. APSA allows only the one system. |
| APA | Uses a comma between name and year, for example (Putnam, 2000). APSA omits the comma: (Putnam 2000). |
| MLA | Cites the surname and page number, with no publication year in the parenthetical. APSA always includes the year. |
In-Text Citations in APSA Style
APSA in-text citations follow the author-date format and can be placed in two positions. The first option puts the last name and the publication year in parentheses at the end of the sentence, with no comma between them. The second option names the writer in the sentence itself and places only the year in parentheses right after.
| Names in the source | In-text example |
|---|---|
| 1 | (Aspen Institute 2005) |
| 2 | (Thistlewaite and Campbell 1960) |
| 3 | (Imai, King, and Nall 2009) |
| 4 or more | (Corbridge et al. 2004) |
When a sentence includes a direct quote, add the page number after the year, separated by a comma: (Davis 2004, 154). A general paraphrase of a source’s overall argument only needs the author’s last name and year, with no page number. To cite more than one source for the same point, list them inside a single set of parentheses in alphabetical order, with each citation separated from the next by a semicolon, as in (Evans 2009; Kovar 1974; Okoli 2014). If a writer published two works in the same year, add lowercase letters after the year in both the in-text citation and the matching reference list entries, for example (Alvarez and Saving 1997a).
Reference List Format in APSA Style
Every source named in the text needs a corresponding entry on the reference list, titled “References,” sorted alphabetically by last name. The first line of each entry is flush left, and every following line is indented. Titles use headline-style capitalization: nouns, verbs, adjectives, and adverbs are capitalized, while short prepositions and coordinating conjunctions stay lowercase unless they open or close the title.
| Source type | Formula and worked example |
|---|---|
| Book | Last Name, First Name. Year. Book Title. City: Publisher. Axler, Sheldon. 2017. Linear Algebra Done Right. New York: Springer. |
| Journal article | Last Name, First Name. Year. “Article Title.” Journal Name Volume: Page Range. Leach, Peter. 1997. “James Paine’s Design for the South Front of Kedleston Hall.” Architectural History 40: 159-70. |
| Website | Last Name, First Name (or Organization). Year. “Page Title.” Site Name. Last modified Month Day, Year. URL. Aspen Institute. 2005. “Congressional Program Report.” Aspen Institute. https://www.aspeninstitute.org. |
Full formatting rules for every source category, including periodicals, datasets, and multimedia, are laid out in the APSA Style Manual’s official reference list guidelines, and the in-text rules above draw on the manual’s parenthetical citation section.
Special Cases: Editors, Chapters, and Missing Information
A few source types do not fit the standard formula above and trip up most first-time APSA writers.
- Edited books and chapters: When citing one chapter from an edited collection, list the chapter author first, then “In” followed by the book title, editor name, and the abbreviation “ed.” before the publication information.
- No credited writer: If a source has an editor or translator but no author, that name takes their place, followed by “ed.” or “trans.” If nobody is credited at all, move the title to the front of the entry instead of inventing one.
- Organizations as the credited name: A report published by an agency or association is listed under that organization’s name, even when the organization is also the publisher.
- Later editions: Add the edition number right after the title, for example Book Title, 3rd ed., so readers know which edition’s page numbers and information apply.
- Same last name, different writers: Repeat the shared last name in every reference rather than using “ibid.” or a dash, since APSA reference lists must stay unambiguous at a glance.
Worked Example: From In-Text Citation to Reference Entry
Here is how a single claim moves from the body of a paper to its matching entry. Suppose a paragraph on interest-group lobbying includes this sentence: “Interdependence generates a dense network of relations among policymakers (Marin and Simmons 1998, 751).” That parenthetical points a reader to one entry, and only one:
| Step | What it shows |
|---|---|
| 1. In-text citation | (Marin and Simmons 1998, 751) tells the reader the claim is available in Marin and Simmons’s 1998 work, on page 751. |
| 2. Matching entry | Marin, Dalia, and Beth Simmons. 1998. “Multinational Trade Finance.” International Studies Quarterly 42: 731-58. |
| 3. Online version | If it exists only online, the entry adds the URL and, when the site lists one, the date it was last updated. |
Every parenthetical citation in a paper should link back to exactly one entry this way, and every entry should be tied to at least one in-text mention. Padding the list with uncited works, or citing a claim with nothing to match it, both break APSA’s basic expectation of a fully linked paper trail.
Citing Government Documents and Laws in APSA
Political science papers frequently cite statutes, treaties, court cases, and government reports, and these follow their own APSA formatting conventions rather than the standard author-date book or article formula. A statute reference typically opens with the name of the act, followed by the public law number, volume and section of the U.S. Code or Statutes at Large, and the year of enactment. Court cases are cited by case name, volume and page of the reporter, and the deciding court and year. Presidential directives follow a similar pattern to an executive order citation, listing the issuing office, the order number, and the year it was signed. For the full breakdown of legal and public document formats, the Lamar University APSA guide to legal and public documents covers statutes, treaties, and congressional records with worked examples.
Common APSA Citation Mistakes
Most APSA errors come from mixing up rules borrowed from APA or Chicago. The comparison below shows the most frequent mistake against the correct APSA format.
Correct: (Putnam 2000) for a paraphrase, and (Putnam 2000, 34) when quoting page 34 directly. No comma before the year, and the page number only appears with a specific quote or data point.
Incorrect: (Putnam, 2000) with a comma after the surname. That comma placement belongs to APA style, not APSA.
Related Citation Guides
These EssayReply guides cover source types that come up often alongside APSA-style political science research.
- How to Cite a Book
- How to Cite a Journal Article
- How to Cite a Government Website
- How to Cite a Law
- How to Cite a Report
- How to Cite a Database
- How to Cite a Thesis
Frequently Asked Questions About APSA Citation Style
What is APSA citation style used for?
APSA citation style is used almost exclusively in political science coursework and journals. It is the format required by the American Political Science Association for its member journals and is commonly assigned in undergraduate and graduate political science classes.
Is APSA the same as Chicago style?
APSA is built on the Chicago author-date system, so the two are very close. The main difference is that Chicago also permits a notes-bibliography option, while APSA journals use only the author-date system.
Do APSA in-text citations need page numbers?
Page numbers are required only when quoting directly or pointing to a specific fact, figure, or data point, for example (Davis 2004, 154). A general paraphrase of a source’s overall argument only needs the author’s last name and year.
How many authors before I use “et al.” in APSA style?
Use “et al.” once a source has four or more authors, both in the in-text citation and, per the APSA Style Manual, in reference list entries with ten or more authors after listing the first seven.
Where can I find the official APSA style manual?
The American Political Science Association publishes the current edition of the APSA Style Manual online, linked in the “What Is APSA Citation Style?” section above, covering formatting rules for every source type referenced in this guide.
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Terry is a Chicago-based writer and editor who creates practical, student-friendly guides on essay writing, research, and citation styles (APA, MLA, and Chicago). He’s spent 15+ years editing educational content and building clear examples that help readers apply rules without guessing. When he’s not revising drafts, he’s usually turning messy notes into clean outlines and hunting down the one detail everyone skips.