When should I use “et al.” in citations?

The abbreviationet al.” (Latin for “and others”) is used to shorten citations of sources with multiple authors.

“Et al.” is used in APA in-text citations of sources with 3+ authors, e.g. (Smith et al., 2019). It is not used in APA reference entries.

Use “et al.” for 3+ authors in MLA in-text citations and Works Cited entries.

Use “et al.” for 4+ authors in a Chicago in-text citation, and for 10+ authors in a Chicago bibliography entry.