APA style uses a simple rule for citing works with multiple authors: for one or two authors, list every name in each citation; for three or more authors, use only the first author’s last name followed by “et al.” every time, including the very first citation. This rule, established in the 7th edition of the APA Publication Manual, is a change from earlier editions that required listing up to five authors on first mention. Here’s how to apply it in every situation you’ll encounter.
Two Authors
When a source has two authors, include both last names in every in-text citation. The punctuation changes depending on whether you name the authors in your sentence (a narrative citation) or place them inside parentheses (a parenthetical citation).
In a narrative citation, connect the names with the word “and”:
- Shumway and Shulman (2015) found that early intervention improved outcomes.
In a parenthetical citation, use an ampersand (&) instead:
- Early intervention improved outcomes (Shumway & Shulman, 2015).
This pattern stays the same no matter how many times you cite the source. There is no shortened form for two-author works.
Three or More Authors
For any source with three or more authors, write only the first author’s last name followed by “et al.” (short for the Latin “et alia,” meaning “and others”). Do this from the very first citation onward.
- Narrative: Adams et al. (2019) argued that the policy was effective.
- Parenthetical: The policy was effective (Adams et al., 2019).
Note the period after “al.” because it is an abbreviation. Never italicize “et al.” in your citations. This rule applies whether the source has 3 authors or 20.
Citing Multiple Sources at Once
When you want to support a point with several sources inside one set of parentheses, separate each citation with a semicolon and arrange them in alphabetical order by the first author’s last name:
- (Adams et al., 2019; Shumway & Shulman, 2015; Westinghouse, 2017)
If you want to highlight one source as most relevant while still acknowledging others, place the key citation first, then add “see also” before the supporting citations:
- (Sampson & Hughes, 2020; see also Augustine, 2017; Melara et al., 2018; Pérez, 2014)
When you’re citing multiple works by the same author or author group, list the surname once and then give the years in chronological order, separated by commas. If a work has no date, place “n.d.” first, and put “in press” last:
- (Zhou, n.d., 2000, 2016, in press)
When Two First Authors Share a Last Name
If your paper cites sources by different people who happen to share the same last name as first author, include the first author’s initials in every citation to avoid confusion, even if the publication years are different:
- (J. M. Taylor & Neimeyer, 2015; T. Taylor, 2014)
If two first authors share both the same last name and the same initials, cite the works in standard format without initials. In the rare case where this still creates confusion, you can include the first author’s full first name in a narrative citation to clarify: “Sarah Williams (2019) stated X, whereas Shonda Williams (2020) stated Y.”
One exception: if multiple authors within the same reference share a surname (for example, two researchers named Chen who co-authored a paper), no initials are needed. Just cite it normally: (Chen & Chen, 2019).
Group and Organizational Authors
When the author is an organization rather than a person, the organization’s name takes the place of an author’s last name. If the organization has a well-known abbreviation, you can introduce it on first use and then use the short form in later citations.
For a parenthetical first citation, place the abbreviation in square brackets:
- First citation: (American Psychological Association [APA], 2017)
- Later citations: (APA, 2017)
For a narrative first citation, place the abbreviation in parentheses before the year:
- First citation: The American Psychological Association (APA, 2017) provided guidelines on treatment.
- Later citations: The APA (2017) provided guidelines on treatment.
If your paper cites two different organizations that share the same abbreviation (for example, the American Psychological Association and the American Psychiatric Association both abbreviate to APA), spell out the full name every time. Using the abbreviation would leave readers unsure which organization you mean. In the reference list, always spell out the full organization name regardless of whether you abbreviated it in the text.
Quick Reference
- 1 author: (Smith, 2020) or Smith (2020)
- 2 authors: (Smith & Jones, 2020) or Smith and Jones (2020)
- 3+ authors: (Smith et al., 2020) or Smith et al. (2020)
- Organization, first use: (World Health Organization [WHO], 2021)
- Organization, later uses: (WHO, 2021)
- Multiple sources in one citation: alphabetical order, separated by semicolons
The key detail to remember: the ampersand (&) goes inside parentheses, while the word “and” is used when the authors’ names are part of your sentence. That distinction applies to every citation format in APA style, whether you have two authors or are introducing a group author abbreviation.