APA in-text citations follow an author-date system: you include the author’s last name and the year of publication every time you reference a source. The citation can appear inside parentheses at the end of a sentence or be woven into the sentence itself. Beyond that basic structure, the formatting shifts depending on how many authors a source has, whether you’re quoting directly or paraphrasing, and a few other common scenarios. Here’s how each one works.
Parenthetical vs. Narrative Citations
Every APA in-text citation takes one of two forms. A parenthetical citation places both the author and the year inside parentheses, separated by a comma:
- Sleep deprivation impairs decision-making in measurable ways (Luna, 2020).
A narrative citation works the author’s name into the sentence itself, with only the year in parentheses right after the name:
- Luna (2020) found that sleep deprivation impairs decision-making in measurable ways.
The author’s name can appear wherever it fits naturally in the sentence. In rare cases, you might mention both the author and the year in the running text, with no parentheses at all: “In 2020, Luna found that sleep deprivation impairs decision-making.” This is fine when it reads naturally, but most of the time you’ll use one of the two standard forms.
One punctuation detail to remember: when a parenthetical citation appears alongside other text inside parentheses, use a semicolon to separate them rather than nesting one set of parentheses inside another. For example: (e.g., falsely balanced news coverage; Koehler, 2016).
How Author Count Changes the Format
The number of authors on a source determines how you write the author portion of your citation.
One author: Use the author’s last name in every citation. Parenthetical: (Luna, 2020). Narrative: Luna (2020).
Two authors: Include both last names every time. In a parenthetical citation, join them with an ampersand: (Salas & D’Agostino, 2020). In a narrative citation, spell out the word “and”: Salas and D’Agostino (2020). This ampersand-vs.-“and” rule is easy to mix up, so keep it in mind.
Three or more authors: Use only the first author’s last name followed by “et al.” (short for the Latin “et alia,” meaning “and others”). This applies from the very first citation onward. Parenthetical: (Martin et al., 2020). Narrative: Martin et al. (2020). Note the period after “al.” since it’s an abbreviation.
Citing Direct Quotes
When you quote a source word for word, APA requires one extra element: a locator that tells the reader exactly where the quoted passage appears. For most sources, this means a page number.
Use “p.” for a single page and “pp.” for a range of pages. Separate a page range with an en dash, and use a comma for discontinuous pages:
- Single page: (Luna, 2020, p. 25)
- Page range: (Luna, 2020, pp. 34–36)
- Discontinuous pages: (Luna, 2020, pp. 67, 72)
In a narrative citation, the page number goes with the year in the parenthetical portion or in a separate set of parentheses after the quoted text: Luna (2020) argued that “direct quote here” (p. 25).
If your source doesn’t have page numbers, such as a webpage or an audiovisual work, provide another locator so the reader can find the passage. A paragraph number (para. 4), a section heading, or a timestamp all work. The goal is to point the reader to the right spot.
When you paraphrase rather than quote directly, page numbers are encouraged but not required. Including them is still helpful, especially when you’re drawing on a specific passage from a long work.
Group and Organizational Authors
When a source is authored by an organization rather than a person, use the organization’s name in place of an author name. The first time you cite it, write out the full name. If the organization has a well-known abbreviation, you can introduce it in brackets on first use and then use the abbreviation in later citations:
- First citation, parenthetical: (World Health Organization [WHO], 2023)
- Subsequent citations: (WHO, 2023)
In narrative form, the same logic applies: World Health Organization (WHO, 2023) reported… followed by WHO (2023) in later references. If the organization doesn’t have a familiar abbreviation, write out the full name each time.
Sources With No Author
When a work has no identifiable author, use the first few words of the reference list entry (usually the title) in place of the author name. Italicize the title if it refers to a standalone work like a book or report, and put it in quotation marks if it’s a shorter piece like an article or chapter. Follow it with the year as usual:
- (“New Findings in Sleep Research,” 2022)
Citing a Source Within a Source
Sometimes you’ll read an author’s work and find them referencing another study you haven’t read yourself. APA calls the study you didn’t read the “primary source” and the one you did read the “secondary source.” To cite the original work, name it in the text and add “as cited in” followed by the source you actually used:
- Parenthetical: (Rabbitt, 1982, as cited in Lyon et al., 2014)
- Narrative: Rabbitt (1982, as cited in Lyon et al., 2014) argued that…
If you don’t know the year of the original work, simply omit it: Allport’s diary (as cited in Nicholson, 2003). Only the secondary source, the one you actually read, goes in your reference list. Use this approach sparingly. Whenever possible, track down and read the original source so you can cite it directly.
Multiple Sources in One Citation
When a single point is supported by more than one source, list all the citations inside one set of parentheses, separated by semicolons. Arrange them in alphabetical order by the first author’s last name, which matches the order they would appear in your reference list:
- (Luna, 2020; Martin et al., 2020; Salas & D’Agostino, 2020)
Multiple Works by the Same Author
If you’re citing two or more works published by the same author in the same year, APA distinguishes them by adding a lowercase letter after the year: 2020a, 2020b, and so on. These letters are assigned in your reference list based on the alphabetical order of the titles, and the in-text citations follow suit:
- (Luna, 2020a)
- (Luna, 2020b)
If the same author published works in different years, simply include both years separated by a comma: (Luna, 2018, 2020).
Quick Reference for Punctuation
A few small punctuation details trip people up, so here’s a summary of the rules that come up most often:
- Use a comma between the author and the year: (Luna, 2020).
- Use an ampersand (&) between two authors in parenthetical citations, but spell out “and” in narrative citations.
- Place a period after “al.” in “et al.” every time.
- Place the parenthetical citation before the period at the end of a sentence: …decision-making (Luna, 2020).
- For block quotes (40 words or more), the parenthetical citation goes after the closing period of the quote.
- Use a semicolon to separate multiple sources within the same parentheses.