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In a reference list, “et al.” is a style-by-style decision, not a universal ban or a universal permission. APA 7 lists every author up to 20 and never uses “et al.” below that count. Chicago 18, AMA (as applied by JAMA) and IEEE all shorten long author lists in the reference list, each at a different threshold. Harvard has no single rule at all. The in-text rule is a separate matter and is much more uniform.
Can you write et al. in a reference list?
It depends on the style, and the confusion online comes from sources that describe one style as if it were all of them. “Et al.” is Latin shorthand for “and others”. In a reference list, whether you may use it depends on how many authors the work has and which style your manuscript, thesis or target journal follows. If the style gives a threshold, you list authors up to it and only then shorten. If you are below the threshold, you write every name.
Reference-list thresholds by style
Each row below comes from a named source checked on 2026-10-28 or 2026-10-29 (listed under Sources). Where a style has no fixed rule, the row says so.
| Style | Authors listed in full | When there are more | In-text form |
|---|---|---|---|
| APA 7th (2020) | Up to and including 20 | 21 or more: first 19 authors, an ellipsis (no ampersand), then the final author. No “et al.” in the list | 3 or more authors: first author plus “et al.” from the first citation |
| Chicago 18th (2024) | Up to 6 | More than 6: first 3, then “et al.” | Author-date text citations list up to 2 authors; more than 2 is first author plus “et al.” |
| AMA, as applied by JAMA | Up to 6 | More than 6: first 3, then “et al.” | Numbered superscript references |
| IEEE | Up to 6 names | More than 6: first author plus “et al.” | Numbered brackets; “et al.” when a reference has 3 or more names |
| Harvard (Cite Them Right variants) | Varies by institution: Newcastle lists all, UCL lists up to 7 | Newcastle: “et al.” only above 10. UCL: 8 or more, first 8 then “et al.” Open University: list all, or use “et al.” after the first author, consistently | 4 or more authors: first author plus “et al.” (Open University, Newcastle, UCL) |
This settles the “never” versus “it depends” argument. For APA the answer is effectively never, because no reference with 20 or fewer authors is shortened. For Chicago, AMA and IEEE the answer is yes, past six authors. For Harvard the answer is whatever your institution’s sheet says.
Examples
These are fictitious author lists written to show the pattern. They are not real publications or people. Only the author element is shown; the rest of the entry follows your style’s template. The example work has eight authors.
- APA 7: all eight are listed, with an ampersand before the last: Adler, J. K., Brandt, L. M., Chen, R., Dlamini, S., Eriksen, P., Fofana, A., Garcia, M., & Haddad, N.
- AMA / JAMA: eight is more than six, so the first three then “et al.”: Adler JK, Brandt LM, Chen R, et al.
- IEEE: more than six, so the first author plus “et al.”: J. K. Adler et al.
- Chicago 18: more than six, so the first three authors followed by “et al.”
- Harvard: with eight authors, Newcastle lists all eight, UCL lists the first eight followed by “et al.”, and Open University accepts listing all or shortening after the first author, if you are consistent.
In-text citation version
For APA 7, name only the first author and “et al.” for any work with three or more authors, including the first time it appears: (Adler et al., 2024) or Adler et al. (2024). This is a change from the 6th edition, which spelled out up to five names at first citation. If two references would shorten to the same “et al.” form, spell out as many names as needed to tell them apart. A worked in-text treatment, including ampersand use, is on multiple authors in-text citation in APA 7; for MLA see example in-text citation in MLA 9.
In numbered styles such as AMA and IEEE, the in-text marker is a number, so the author-count rule only matters in the reference list and in running prose. See the IEEE reference format guide and the AMA citation style guide for the full patterns.
Common errors
- Writing “et al.” in an APA reference list for a work with 20 or fewer authors. List them all.
- Using the in-text threshold in the list. APA’s in-text “3 or more” rule does not shorten the reference entry.
- Carrying one style’s cut-off into another, for example using Chicago’s six-then-three rule in an APA thesis.
- Using an ellipsis where the style wants “et al.” APA’s ellipsis form is for 21 or more authors only, and it ends with the final author’s name.
- Trusting a reference manager’s output without checking which style file it applied.
For manuscripts and theses
Your target journal’s author instructions override the general manual. JAMA’s own instructions, for example, apply AMA style with the six-then-three rule, and the journal’s text is what a JAMA submission is held to. Before submitting, check the instructions for the author-count rule, then reconcile your reference manager’s output against it: open the style file, check how it handles author counts, and spot-check one reference with more authors than the cut-off. If no installed style matches the journal, editing a CSL citation style shows how to adjust one. For a thesis, your institution’s handbook takes precedence over the style manual in the same way.
Style-guide edition
The figures above reflect APA 7th edition (2020), Chicago Manual of Style 18th edition (2024), the AMA rule as stated in JAMA’s Instructions for Authors, and the IEEE Reference Style Guide for Authors, all checked 2026-10-29. The Chicago figures are the 18th-edition rule, so check any older Chicago guide against it before copying its numbers.
FAQ
Can you write et al in a reference list?
Yes in Chicago 18, AMA/JAMA, IEEE and some Harvard variants, once the author count passes that style’s threshold. Not in APA 7 for 20 or fewer authors, where every author is listed.
How do I create an in-text citation in APA 7th edition?
Use the author’s surname and year: (Adler, 2024) or Adler (2024). Three or more authors give the first author plus “et al.” at every citation, including the first.
Does APA use an ampersand?
In the reference list, yes: the ampersand goes before the final author, for two to 20 authors. In 21-plus author entries, an ellipsis replaces it. In-text rules for the ampersand are covered on the APA in-text multiple authors guide.
Is the reference-list rule the same as the in-text rule?
No. In APA the in-text rule shortens at three authors while the list shortens only at 21; in Chicago the in-text cut-off is more than two authors and the list cut-off is more than six. See also the definition of a parenthetical citation.
Sources
- APA, Guide to What’s New in the 7th Edition, https://apastyle.apa.org/instructional-aids/whats-new-7e-guide.pdf, checked 2026-10-29.
- University of Chicago Press, Chicago Manual of Style 18th edition, What’s New (sections 13.23 and 13.107), https://www.chicagomanualofstyle.org/help-tools/what-s-new.html, checked 2026-10-29.
- JAMA Network, JAMA Instructions for Authors, https://jamanetwork.com/journals/jama/pages/instructions-for-authors, checked 2026-10-28. This is the journal’s application of AMA style.
- IEEE, IEEE Reference Style Guide for Authors, https://docs.google.com/document/d/e/2PACX-1vSBoV_hTIURPZKtQkxI6bAONJtjyDLxQIUvCHi-XPzD8NKLcxRfZrpvQLFrjWZ3M6FFR_Obau3R-t63/pub, checked 2026-10-29. It states that IEEE publications list up to six names, that more than six takes the primary author plus “et al.”, and that “et al.” is used in text when a reference has three or more names.
- Harvard variants: UCL Library, Harvard authors, https://library-guides.ucl.ac.uk/harvard/authors; Newcastle University, Cite Them Right Harvard Style Sheet (2025); The Open University, Quick guide to Harvard referencing (Cite Them Right), all checked 2026-10-28.
