Answered By: Theresa Bell
Last Updated: Dec 18, 2019     Views: 24799

APA 6th Edition

According to the American Psychological Association (2010), "do not include retrieval dates unless the source material may change over time (e.g., Wikis)" (p. 192). Wikis are designed to change over time, and so references to wikis should include retrieval dates. All other resource types (e.g., journal articles, books, web pages) can be assumed to be in their final forms and therefore references to them do not require retrieval dates. Please see "How to Cite Wikipedia in APA Style" from the APA Style Blog for an example of a reference to a wiki post. 


American Psychological Association. (2010). Publication manual of the American Psychological Association (6th ed.). Washington, DC: Author. 

APA 7th Edition

Per the 7th edition rules, authors should

provide a retrieval date in the source element when citing an unarchived (e.g., not stable) work that is likely or meant to change. Including this date indicates to readers that the version of the work they retrieve may be different from the version you used. (American Psychological Association, 2020, p. 290)

Retrieval dates aren't necessary when referencing works that have archived versions; in fact, "the majority of references do not include retrieval dates; the types that might are noted in the applicable reference examples in Chapter 10" (American Psychological Association, 2020, p. 290).

If you are working with a resource type where the reference includes a retrieval date, the format for the information is "Retrieved Month day, year, from URL". See page 290 and the relevant examples in Chapter 10 of the APA Style manual for more information.


American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.).