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APA Style

This guide contains tips for how to maximize your Academic Writer experience plus additional resources to assist with APA style.


Learn how to use abbreviations, including how to introduce them and how to use Latin and scientific abbreviations.

Academic Writer

© 2023 American Psychological Association.

Overview of Abbreviation Guidelines

1) Before using an abbreviation, include the full spelling of the phrase followed by the abbreviation in parenthesis.

  • Only introduce an abbreviation if you will use the abbreviation at least three times in the chapter. Once the abbreviation is introduced, only use the abbreviation.


Abbreviation with an in-text citation:

  • Introduction to the term: The Center for Disease Control (CDC, 2019) stated...
  • Subsequent use of the term: The CDC (2019) suggests…

Abbreviation in Text:

  • Introduction to the term: Paid time off (PTO) is offered… 
  • Subsequent use of the term: Employees use PTO…

2) If an abbreviation is listed in the dictionary and the listing is not labeled "abbr," it can be used in the text without a definition. 


  • AIDS
  • ACTH
  • ESP
  • HIV

3) Except for units of measurement, abbreviations can be written as both singular or plural abbreviations.


  • An early intervention service (EIS) is... EISs are used...

4) Some abbreviations should include periods.


  • Use periods when abbreviating names: J. M. Smith
  • If abbreviating the United States, abbreviate it as "U.S." only when the abbreviation is used as an adjective. If abbreviating the "United Kingdom," abbreviate it as "U.K." Examples: U.K.flag, U.S. Treasury. When referring to a county as a noun, spell out the country's name. Example: The United States is an amazing place to live. 
  • Use periods without spaces for Latin abbreviations: a.m., i.e., e.g. 

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