APA format requires two components every time you cite evidence: a brief in-text citation where you use the source and a full reference list entry at the end of your paper. The in-text citation gives the reader an author and year, while the reference list provides everything needed to find the original source. Getting both parts right is straightforward once you understand the patterns.
How In-Text Citations Work
Every piece of evidence you bring into your paper, whether it’s a direct quote, a paraphrased idea, or a data point, needs an in-text citation that includes the author’s last name and the year of publication. APA gives you two ways to format this.
A parenthetical citation places both the author and year inside parentheses at the end of the sentence: “Sleep deprivation impairs working memory (Walker, 2017).” A narrative citation weaves the author’s name into the sentence itself and puts only the year in parentheses: “Walker (2017) found that sleep deprivation impairs working memory.” Both formats are equally correct. Use whichever reads more naturally in context, and feel free to alternate throughout your paper.
Citing Direct Quotes
When you quote a source word for word, you need one extra piece of information beyond the author and year: a page number. This applies to both parenthetical and narrative citations. Use “p.” for a single page and “pp.” for a range. A few formatting details matter here:
- Single page: (p. 25)
- Page range: (pp. 34–36), connected with an en dash
- Discontinuous pages: (pp. 67, 72), separated by a comma
A parenthetical citation with a page number looks like this: “Sleep-deprived participants showed a 40% decline in recall accuracy” (Walker, 2017, p. 142). A narrative version would read: Walker (2017) reported that “sleep-deprived participants showed a 40% decline in recall accuracy” (p. 142).
If your source has no page numbers, which is common with websites and some e-books, provide another locator so the reader can find the passage. A paragraph number (para. 4), a section heading, or a combination of both (Discussion section, para. 2) all work.
Paraphrasing Without Page Numbers
When you put a source’s idea into your own words, you still cite the author and year, but the page number is encouraged rather than required. APA recommends including it when it would help the reader locate the relevant passage in a long work, but omitting it is not an error. A paraphrase citation looks like this: Chronic sleep loss has measurable effects on cognitive performance (Walker, 2017). Keep the citation close to the evidence it supports, typically at the end of the sentence or clause where the borrowed idea appears.
Handling Multiple Authors
The rules change depending on how many authors a source has. For one or two authors, list every name in every citation: (Smith, 2020) or (Smith & Jones, 2020). For three or more authors, list only the first author followed by “et al.” (Latin for “and others”) starting from the very first citation: (Smith et al., 2020). You never need to list all the names in the in-text citation, even the first time you mention the source. The full author list goes in the reference list entry instead.
Group authors like government agencies or organizations are spelled out in full. If a group name is long and has a well-known abbreviation, you can introduce the abbreviation in the first citation and use it afterward: (World Health Organization [WHO], 2023) for the first mention, then (WHO, 2023) for subsequent mentions.
Building a Reference List Entry
Every in-text citation must have a matching entry in the reference list at the end of your paper. Each entry follows a four-element template: author, date, title, and source. These four pieces appear in that order, separated by periods.
Here is the general pattern for a journal article:
Author, A. A., & Author, B. B. (Year). Title of article in sentence case. Title of Periodical in Title Case and Italics, Volume(Issue), Page range. https://doi.org/xxxxx
A few formatting rules to keep in mind: only the first word of an article title is capitalized (plus proper nouns and the first word after a colon). Journal names, book titles, and similar larger works are italicized. If a DOI (a permanent digital link) exists, include it as a clickable URL at the end. If no DOI is available but you accessed the work online, include the regular URL.
For a book, the pattern shifts slightly. The publisher name serves as the source element instead of a journal title: Author, A. A. (Year). Title of book in sentence case and italics. Publisher Name. https://doi.org/xxxxx
When a source is missing one of the four elements, say there’s no identifiable author or no date, APA has specific substitutions. Use the title in place of a missing author, and use “n.d.” (no date) in place of a missing year.
Citing Websites and Online Sources
Websites follow the same four-element structure. The author is whoever is responsible for the content, which could be an individual or an organization. The date is when the content was published or last updated. The title is the page or article title, and the source includes the site name (unless the site name is the same as the author) plus the URL.
A typical website reference looks like this:
National Institute of Mental Health. (2024, March). Anxiety disorders. https://www.nimh.nih.gov/health/topics/anxiety-disorders
Because the site name and the author are the same organization, you list it once as the author and skip repeating it as the source. The in-text citation would be (National Institute of Mental Health, 2024).
Citing AI-Generated Content
If you use output from a tool like ChatGPT or Gemini as evidence, APA has a specific format. The author is the company that developed the tool, not the AI itself, because APA considers authorship a human responsibility. The date is the specific day you had the conversation.
The reference template for a specific AI chat:
AI Company Name. (Year, Month Day). Title of chat [Generative AI chat]. Tool Name. URL of the chat
For example: OpenAI. (2025, June 15). Explaining citation formats [Generative AI chat]. ChatGPT. https://chat.openai.com/share/xxxxx
If you want to reference the tool generally rather than a specific conversation, use the year the tool was most recently updated and provide the tool’s main URL. When the prompts you used are important to your argument, describe them in your text or include them in an appendix. The reference itself points to the chat, not to individual prompts.
Putting It All Together
A practical workflow for citing evidence in APA format looks like this: as you draft, drop in parenthetical or narrative citations each time you use a source. Include page numbers for every direct quote. After you finish drafting, build your reference list alphabetically by the first author’s last name. Double-check that every in-text citation has a matching reference entry, and that every reference entry is actually cited somewhere in your paper. The two lists should mirror each other exactly.
For works with three or more authors, confirm you’re using “et al.” in the text while listing all authors in the reference entry. For direct quotes, verify that every one includes a page number or alternative locator. These two details are where most APA citation errors happen, and catching them in a final pass takes only a few minutes.