AMA Citation Style: A Complete Guide with Examples

The American Medical Association (AMA) citation style is the standard for medical and scientific writing, particularly in fields like medicine, public health, and other health sciences. Unlike author-date styles such as APA or MLA, AMA uses a unique numbered system for both in-text citations and reference lists. Mastering this style ensures clarity, consistency, and academic integrity in your scholarly work.

This comprehensive guide will walk you through the core principles of AMA style, providing practical examples for various source types to help you cite with confidence.

Understanding AMA Style: Core Principles

AMA style follows the "Vancouver" system, characterized by numerical citations. Here are its fundamental principles:

• Numbered Citations: Sources are cited in the text using superscript Arabic numerals (e.g., ¹, ², ³) in the order they first appear.
• Sequential Numbering: Each unique source is assigned a number sequentially throughout the document. If you cite the same source again, you use its original assigned number.
• Reference List: A numbered reference list at the end of your document corresponds to the in-text citations, providing full bibliographic details for each source. This list is ordered numerically, not alphabetically.
• Conciseness: AMA emphasizes brevity. Titles of journals are abbreviated according to the National Library of Medicine (NLM) catalog, and author lists are often truncated.

In-Text Citations: How to Reference Your Sources

In-text citations in AMA style are straightforward once you understand the numbering system.

Basic In-Text Citation

Place the superscript number immediately after the information or statement being cited. It should appear outside periods and commas, but inside colons and semicolons.

Example: The prevalence of cardiovascular disease has steadily increased over the past decade.¹ A recent study indicated a strong correlation between diet and heart health.²,³

Citing Multiple Sources

When citing multiple sources for a single statement, list their corresponding numbers in sequence, separated by commas without spaces. For three or more consecutive numbers, use an en dash.

Examples: Several studies confirm this finding.¹,²,⁴ New research suggests improved patient outcomes with this treatment regimen.⁵⁻⁸

Citing Direct Quotes

Direct quotes are rare in scientific writing, but when used, they should be enclosed in quotation marks, followed by the superscript number, and then typically include the page number from which the quote was taken.

Example: As Smith et al. stated, "The novel therapy demonstrated remarkable efficacy in phase II trials"¹(p25).

Author Names in Text

If you mention an author's name in your sentence, the citation number still follows the statement or idea, not necessarily the author's name itself.

Example: According to Johnson et al., the new drug shows promising results.¹ The findings by Johnson et al. further support the hypothesis.¹

The Reference List: Detailing Your Sources

The reference list, titled "References," is where you provide complete bibliographic information for every source cited in your text. This list is ordered numerically based on the first appearance of the citation in your document.

General Rules for the Reference List

• Numbered List: Each reference begins with its assigned number, followed by a period.
• Journal Abbreviation: Journal titles are abbreviated according to the NLM Catalog. If you're unsure, search for the full journal title on the NLM website.
• Author List: List the first six authors, followed by "et al." if there are more than six. For fewer than seven authors, list all. Authors' last names come first, followed by their initials (no periods or spaces between initials).
• Punctuation: Pay close attention to the specific punctuation (commas, periods, colons, semicolons) as it is crucial for AMA style.

Examples of Common Source Types

Here are detailed examples for the most frequently cited sources:

Journal Article (Print)

Format: Author(s). Article title. Journal Abbreviation. Year;Volume(Issue):Pages.

Example:

1. Smith J, Jones A. The impact of diet on cardiovascular health. N Engl J Med. 2023;388(12):1123-1129.

Journal Article (Online with DOI)

Format: Author(s). Article title. Journal Abbreviation. Year;Volume(Issue):Pages. doi:DOI.

Example:

1. Miller C, Davis S, Wilson K. Advances in gene therapy for inherited disorders. Mol Ther. 2022;30(5):1870-1885. doi:10.1016/j.ymthe.2022.03.001

Note: If no DOI is available, but the article is online, include the URL and access date.

Format (online, no DOI): Author(s). Article title. Journal Abbreviation. Year;Volume(Issue):Pages. Published [date]. Updated [date, if applicable]. Accessed [date]. URL.

Example:

1. Brown L, White R. Telemedicine in rural healthcare: a review. J Rural Health. 2021;37(4):450-460. Published October 1, 2021. Accessed January 15, 2024. https://www.jrhonline.org/article/S0890-4477(21)00078-X/fulltext

Entire Book

Format: Author(s). Title of Book. Edition number (if applicable). Publisher; Year.

Example:

1. Goldman L, Schafer AI. Goldman-Cecil Medicine. 26th ed. Elsevier; 2020.

Chapter in an Edited Book

Format: Author(s) of chapter. Chapter title. In: Editor(s) of book, eds. Title of Book. Edition number (if applicable). Publisher; Year:Pages.

Example:

1. Fauci AS, Lane HC. HIV/AIDS: a global perspective. In: Jameson JL, De Groot LJ, eds. Endocrinology. 8th ed. Saunders; 2021:1450-1465.

Website

Format: Author(s) [if available]. Title of specific page. Name of Website. Published [date]. Updated [date, if applicable]. Accessed [date]. URL.

Note: If no author, start with the title of the specific page or the organization name.

Example:

1. American Heart Association. Healthy eating tips. Heart.org. Published November 1, 2023. Accessed February 2, 2024. https://www.heart.org/healthy-eating

Conference Abstract or Presentation

Format: Author(s). Title of paper or abstract. Paper presented at: Name of Conference; Date of Conference; Location of Conference.

Example:

1. Chen H, Kim S. Novel biomarkers for early cancer detection. Paper presented at: American Association for Cancer Research Annual Meeting; April 5-10, 2023; Orlando, FL.

Government Report or Publication

Format: Author(s) [usually government agency]. Title of Report. Report No. [if applicable]. Publisher; Year. URL [if accessed online].

Example:

1. Centers for Disease Control and Prevention. National Diabetes Statistics Report, 2020. US Dept of Health and Human Services; 2020. https://www.cdc.gov/diabetes/data/statistics-report/index.html

Personal Communication

Personal communications (e.g., emails, interviews, informal conversations) are cited only in the text and not included in the reference list.

Example: According to Dr. Jane Doe (oral communication, January 10, 2024), the preliminary results are promising.

Key Tips for Accuracy and Consistency

• Be Consistent: Once you assign a number to a source, always use that same number when citing it again.
• Proofread Carefully: Small errors in punctuation, capitalization, or abbreviation can compromise the professionalism of your work. Double-check every entry against the official AMA Manual of Style. For an extra layer of confidence, services like Humanize can help ensure your citations are perfectly formatted and consistent, catching even the most subtle errors.
• Use Citation Management Tools: Tools like Zotero, Mendeley, or EndNote can help automate the citation process, reducing the risk of errors, though always verify the output.
• Consult the Manual: For less common source types or complex situations, always refer to the AMA Manual of Style, 11th edition, which is the definitive guide.
• Understand Your Field's Nuances: While AMA is standard, specific journals or institutions might have minor variations or preferences. Always check the "Instructions for Authors" for your target publication.

Mastering AMA citation style is an essential skill for anyone contributing to medical or scientific literature. By adhering to these guidelines and practicing with examples, you can produce well-cited, credible, and professional academic work.

Final Checklist for AMA Citations

Before submitting your work, run through this quick checklist:

• Are all in-text citations numbered sequentially in order of first appearance?
• Are all in-text citations formatted as superscripts?
• Does the reference list appear at the end of the document, titled "References"?
• Is the reference list numbered, with entries corresponding to the in-text citations?
• Are journal titles abbreviated correctly (NLM catalog)?
• Are author lists truncated correctly (first 6, then et al.)?
• Is the punctuation precise for each source type?
• Are page numbers included for direct quotes?
• Are DOIs included for online journal articles where available?
• Are access dates and URLs provided for websites and online-only sources without DOIs?

By diligently following these steps, you'll ensure your work meets the high standards of AMA citation, enhancing your credibility and the readability of your research.