AMA citation style is the referencing system defined by the AMA Manual of Style, published by the American Medical Association. It uses superscript Arabic numerals in the text and a reference list numbered in citation order. It is the house style of JAMA and a large share of medical, nursing, and biomedical journals published in the United States, so any author submitting to those titles needs to know it.
AMA belongs to the same family of numbered styles as Vancouver, and the two are frequently confused. This guide sets out the AMA rules with examples and then draws the contrast explicitly.
AMA cites sources with a superscript number placed at the point of citation. The defining detail is placement: in AMA, the superscript numeral goes after commas and periods. For example: The trial reported a significant reduction in mortality.¹ When a clause cites several sources, use commas with no spaces, and a hyphen for ranges: as shown in earlier work.²,⁴,⁷ or in three trials.²⁻⁴
Each source keeps the number it received the first time it appeared. Reusing a source later in the paper means reusing its original number, exactly as in Vancouver. Because the numbering is positional, inserting a citation renumbers the rest of the document, so a reference manager is essential for anything longer than a short letter.
References appear in a numbered list ordered by first appearance. Author names are inverted with initials, journal titles use NLM abbreviations, and up to six authors are listed before et al.
Journal article: Author AA, Author BB, Author CC. Title of article. Abbreviated Journal Name. Year;Volume(Issue):Page-Page. doi:xx.xxxx
Harrison KL, Diaz M, Feldman S, et al. Sepsis bundles and 30-day mortality. JAMA. 2023;329(14):1180-1189. doi:10.1001/jama.2023.4421
Book: Author AA. Title of Book. Edition. Publisher; Year.
Friedman LM, Furberg CD, DeMets DL. Fundamentals of Clinical Trials. 5th ed. Springer; 2015.
Online source: Author/Organisation. Title. Website Name. Published Month Day, Year. Accessed Month Day, Year. URL
Note that AMA italicises journal and book titles, includes the DOI where available, and uses an en dash style page range without repeating shared digits in some house variants. Always confirm against the target journal's own instructions, because JAMA and its sister journals apply small variations on top of the manual.
Because both are numbered, citation-order styles that use NLM journal abbreviations, AMA and Vancouver look similar at a glance. The practical differences are:
- Superscript by default. AMA consistently uses superscript numerals; Vancouver journals vary between parentheses, brackets, and superscript.
- Placement after punctuation. AMA superscripts follow commas and periods; some Vancouver variants place the marker before the period.
- Italics and DOI. AMA italicises titles and routinely includes the DOI.
If your target journal specifies "AMA style," do not substitute a generic Vancouver template, because copy editors will flag the punctuation and superscript differences. Our manuscript editing team handles these house-style conversions routinely, and our medical writing service prepares clinical manuscripts in AMA from the outset.
For United States medical journals, reference formatting is part of the first impression an editor forms. A reference list that mixes AMA and another style, or that spells out journal titles, signals that the authors did not read the instructions, which is rarely the message you want to send before peer review. Reference errors are also a common reason manuscripts are returned for correction, adding weeks to an already slow process. Our overview of choosing a target journal explains how to identify house-style requirements before you format, and our explainer on in-text citations versus the reference list covers the underlying logic that AMA, Vancouver, and APA each implement differently.
For authors preparing a high-stakes submission, the safest approach is to draft in a reference manager configured for AMA, then verify the final list line by line against the journal's instructions, or hand that verification to an editor who does it daily.
Citing Datasets, Preprints, and Online-First Articles in AMA Style
Modern biomedical writing increasingly cites sources that the classic AMA reference list rules never anticipated. For an online-first article that has a DOI but no final volume, issue, or page numbers, cite the authors, title, journal, and year, then add "Published online" with the date and the DOI. Once the article reaches an issue, update the entry with the full citation. For a preprint, name the server (for example, medRxiv or bioRxiv), give the posting date, label it clearly as a preprint, and include the DOI so readers can find the version of record if one later appears. For a dataset, list the investigators or organisation, the dataset title, the repository (such as Dryad or Figshare), the year, and the accession number or DOI. Treating these sources with the same rigour as a journal article keeps your evidence trail reproducible, which is exactly what reviewers of a systematic review expect. To format these entries quickly and consistently, paste the DOI into our free citation builder, which builds the AMA reference and the matching in-text marker together.