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AMA citation style is the numbered referencing system of the AMA Manual of Style, used by JAMA and the JAMA Network journals. Sources are numbered in the order they first appear, shown as superscript numerals in the text, and listed in that same order at the end. This guide covers the 11th edition (2020) and sets out the patterns that university library style guides and the JAMA instructions for authors agree on.
What AMA citation style is
AMA is a numbered (citation-sequence) style rather than an author-date style. The first source you cite is 1, the next new source is 2, and so on. There are no author names or years in the running text: the number points to the entry in the reference list.
The reference entries themselves are compact. Author surnames are followed by initials without periods, journal names are abbreviated, and the publication details follow in a fixed order. If you are comparing AMA with the other numbered medical style, see our guide to Vancouver referencing style, and for a wider map of styles see citation styles and referencing formats.
Who maintains it and what it covers
The style is defined in the AMA Manual of Style: A Guide for Authors and Editors. The 11th edition was published by Oxford University Press in 2020, and the Manual is hosted online by Oxford Academic, where a page of updates records changes made since publication. Recent entries on that page include clarified preprint citation in 2020, guidance on large language models and chatbots added in August 2024 (sections 3.15.12 and 3.15.13), and a section on short-form references (3.18) added in May 2026. The patterns below come from the JAMA instructions for authors and from two university library guides, the University of South Carolina and West Virginia University.
The Manual covers more than references: it is a general style manual for medical writing and publishing. JAMA applies it to manuscripts, and its instructions for authors describe a Word file, 10-, 11- or 12-point type, double spacing, and a fixed section order (title page, abstract, text, references, legends, tables). For the journal’s policy on artificial intelligence in authorship, see our guide to the AMA Manual of Style and the JAMA Network AI authorship policy.
How to format AMA citations
- Number sources in order of first citation. Begin with 1 for the first source you use. Number by order of appearance, not alphabetically.
- Use superscript Arabic numerals in the text. The same applies to tables and figure legends in JAMA’s instructions.
- Place the numeral by the punctuation. Superscripts go outside periods and commas and inside colons and semicolons, according to the West Virginia University and University of South Carolina guides and JAMA.
- Combine citations correctly. Join the first and last numbers of a closed series with a hyphen and separate other numbers with commas and no spaces, for example 1-3,6,8 (University of South Carolina example). West Virginia University adds that two references are not combined under a single number.
- Name authors in the sentence when you need to. With two authors, give both surnames; with three or more, give the first author’s surname followed by et al (University of South Carolina).
- List every source in the reference list, in numerical order. List all authors unless there are more than six; if there are more than six, list the first three followed by et al. Use surname plus initials without periods.
- Abbreviate journal names and italicise them. Abbreviations follow the PubMed journal list (JAMA, both library guides).
- Add the DOI when one exists. West Virginia University advises citing the DOI rather than the URL when one is provided. In JAMA’s own examples it appears as
doi:10.xxxx/xxxxx.
Examples
| Source type | Example | Source of pattern |
|---|---|---|
| Journal article | Ceraulo AS, Bytomski JR. Infectious mononucleosis management in athletes. Clin Sports Med. 2019;38(4):551-561. doi:10.1016/j.csm.2019.06.002 | University of South Carolina Libraries |
| Book | Anderson KM. Enhancing Resilience in Survivors of Family Violence. Springer; 2010. | West Virginia University Libraries |
| Book chapter | Sisk JE. Cardiac catheterization. In: Krapp K, ed. The Gale Encyclopedia of Nursing & Allied Health. Gale Group; 2002:407-412. | West Virginia University Libraries |
| Web page | Centers for Disease Control and Prevention. Health equity considerations and racial and ethnic minority groups. Centers for Disease Control and Prevention. Updated July 24, 2020. Accessed August 3, 2020. | University of South Carolina Libraries (a URL follows the access date) |
In a journal reference the order is authors, article title, journal, then year, volume, issue in parentheses and pages. The 11th edition no longer asks for a publisher location in book references, which is why the book example has only publisher and year.
Strengths and limits
Strengths. The text carries only a numeral, with no author names or years, and the reference list follows citation order, so each number leads straight to its entry. Entries follow a fixed element order and, in the 11th edition, omit the publisher location for books. If you format references with software, see our EndNote guide.
Limits. Renumbering is required whenever you insert or remove a source by hand, so manual numbering is error prone. Library guides can differ in minor points, so confirm unusual source types against the Manual or the journal. JAMA also states that AI tools must not be used to generate or format references, so check each entry yourself. A personal communication does not go in the reference list: it is given in parentheses in the text, and JAMA requires a signed permission statement from each source. Always follow the target journal’s own instructions, since journals apply the style with their own adjustments.
Alternatives to AMA
Which style you use is usually set by the journal, publisher or institution. These related CASRAI pages cover other options.
| Style or topic | Where to read more |
|---|---|
| Vancouver (another numbered style) | Vancouver referencing style |
| Overview of APA, MLA, Chicago and other styles | Citation styles and referencing formats |
| Tools that format a style for you | How to use EndNote |
Frequently asked questions
Is AMA style numbered or author-date?
Numbered. Sources are numbered by order of first citation and cited with superscript numerals; the reference list follows the same order.
Where does the superscript number go relative to punctuation?
Outside periods and commas, and inside colons and semicolons.
How do I cite several sources at once?
Use a hyphen for a closed run and commas without spaces for the rest, for example 1-3,6,8.
How many authors do I list in the reference list?
All of them, up to six. If there are more than six, list the first three followed by et al.
Do I include a DOI?
Yes, when the source has one. The University of South Carolina guide asks for a DOI on journal articles that have one, and West Virginia University says a DOI is preferable to a URL.
Does AMA use initials with periods?
No. Surnames are followed by initials without periods, as in “Ceraulo AS, Bytomski JR.”
How do I cite a personal communication?
Give it in parentheses in the text and leave it out of the reference list. JAMA requires signed permission from each source.
Can I use AI to format my references?
JAMA’s instructions say AI must not be used to generate or format references. Use a reference manager and check each entry against the style.
Which edition of AMA style is current?
The 11th edition (2020) is the one this guide follows. The online Manual records later updates, including short-form references added in May 2026.
Sources
- JAMA Network, Instructions for Authors, https://jamanetwork.com/journals/jama/pages/instructions-for-authors (checked 2026-10-28).
- Oxford Academic, AMA Manual of Style, updates to the Manual, https://academic.oup.com/amamanualofstyle/pages/about/updates-to-the-manual (checked 2026-10-28).
- University of South Carolina Libraries, “AMA 11” citation guide, https://guides.library.sc.edu/citation/ama (checked 2026-10-28).
- West Virginia University Libraries, “AMA Citation Style Guide”, https://libguides.wvu.edu/ama (checked 2026-10-28).
