When should I use et al. in citations?

How you use “et al.” in citations depends on the style guide you are using.

In MLA, “et al.” is used both for in-text citations and the Works Cited page when a source has three or more authors.

In APA 6th edition, works with three to five authors are listed using “et al.” after the first citation. In APA 7th edition, works with three or more authors are listed using “et al.” from the first in-text citation.

In Chicago style, works with four or more authors are listed using “et al.” from the first citation.