AMA Style: The Complete Citation Guide

What AMA style is

AMA style is the citation and writing standard of the American Medical Association, set out in the AMA Manual of Style (currently the 11th edition). It is used by many medical journals and by health-sciences programmes — medicine, public health, pharmacy and allied fields — particularly in North America, though UK and international students meet it too. If your course or target journal specifies AMA, this is the style your references must follow.

Like Vancouver and IEEE, AMA is a numbered system rather than an author–date one, so sources are identified by a number rather than by author and year. Its distinctive surface feature is that the in-text numbers are superscript, sitting slightly above the line, which keeps them unobtrusive in dense clinical prose. The underlying logic — number in citation order, reuse the number, list references numerically — will be familiar if you have used Vancouver, but the formatting details differ.

The superscript principle

The rule at the heart of AMA is the same as for any numbered style: sources are numbered in the order they are first cited, and each number stays with its source. The first source you cite is 1, the next new source is 2, and a later return to source 1 reuses the number 1. The reference list at the end is therefore in citation order, not alphabetical order.

Because the citation's meaning depends on its position, inserting a new source into a finished draft shifts every later number, in both text and list. As with the other numbered styles, this makes a reference manager the practical default for any document of length — renumbering by hand across a long manuscript is slow and a common source of mismatches.

In-text citations

Place a superscript number at the point in your sentence where you use the source. AMA's convention is that the superscript usually sits after any punctuation such as a comma or full stop, with no space before it. You do not give a page number in the in-text citation, even for a quotation (a specific page can be added in the reference or, for a direct quote, beside the superscript using the AMA "(p X)" convention where required).

Notice how the superscripts keep the sentence almost free of citation clutter — a key reason AMA suits clinical writing, where a single statement may rest on several studies. The reader's eye stays on the medicine, and the supporting evidence is a glance away in the numbered list.

Citing multiple or repeated sources

When several sources support one statement, give their numbers together in the superscript, using commas with no spaces for separate numbers and a hyphen for a continuous range:

• Separate sources: ^1,3,5
• A continuous run: ^2-4 rather than ^2,3,4
• A mix: ^1,4-6,9

And, once more, the rule everyone must internalise for numbered styles: a source keeps its first number for the whole document. Return to the first source you cited and it is still superscript 1 — never a new number assigned at the point of reuse. Breaking this produces duplicate reference entries and breaks the one-to-one mapping the system depends on.

The reference list

At the end of the document, under the heading References, sources are listed numerically in citation order, each prefixed by its number (on the line, not superscript, in the list itself). Entries are compact and abbreviated. The general shape for a journal article is: Authors. Article title. Abbreviated Journal Name. Year;volume(issue):pages. doi.

A characteristic AMA detail is that the article title is in sentence case (only the first word and proper nouns capitalised) and is not in quotation marks, while the journal name is abbreviated and italicised. The punctuation — a full stop after the title, the semicolon before the year-volume block, the colon before the pages — does a lot of identifying work, so copy it precisely.

Authors and journal titles

AMA formats authors as surname followed by initials, with no full stops or spaces in the initials — "Okonkwo A", "Smith JR". The author rule is the detail most often confused with Vancouver: in AMA, you list up to six authors; if there are seven or more, you list only the first three followed by "et al". (Vancouver, by contrast, lists the first six before "et al".) Getting this threshold right is a quick win, because it is easy to apply once you know it.

Journal titles are abbreviated using the standard PubMed/NLM abbreviations — "New England Journal of Medicine" becomes "N Engl J Med", "Journal of the American Medical Association" becomes "JAMA". As with Vancouver, you should not abbreviate by guesswork; export the citation from PubMed or let your reference manager apply the abbreviation.

Reference examples

Journal article

Journal article with seven or more authors

Book

Chapter in an edited book

Website / online report

Two details to copy carefully: AMA omits the publisher location for books (just the publisher and year), and online sources carry an "Accessed [Month Day, Year]" before the URL. The DOI, where available, is given as "doi:10…." with no space and is preferred over a URL for journal articles.

Reference managers and AMA

Because AMA shares the positional-numbering challenge of all numbered styles, a reference manager is the sensible default for any substantial piece of writing. Zotero, Mendeley and EndNote all offer an AMA output style: you insert citations as you write, the software assigns and continuously renumbers the superscripts, and it builds the reference list in citation order with the correct author threshold, PubMed journal abbreviations and punctuation. This removes exactly the two most error-prone parts of AMA by hand — the renumbering and the abbreviations — and is well worth the short setup time on a dissertation or manuscript.

AMA vs Vancouver vs APA

AMA and Vancouver are close relatives — both numbered, both medical — and students often have to switch between them. The differences worth remembering are AMA's superscript numbers (Vancouver allows brackets too) and the author threshold (AMA: first three then "et al" for seven or more).

Citing other sources in AMA

Health-sciences writing draws on more than journals and books, and AMA has forms for the sources students increasingly need. The logic never changes — authors, title, source details, a date and a way to locate it — but a few source types are worth seeing explicitly.

Online-only or preprint article

For an article published ahead of print or on a preprint server, give the DOI and, where relevant, note the status. Preprints have not been peer-reviewed, so flag them in your text as well as your reference:

Clinical practice guideline or report

Data set

Two broader AMA conventions are worth knowing while you are here. First, AMA writing has strong expectations about numbers, units and statistics — it prefers SI units, has rules for expressing P values and confidence intervals, and uses numerals for most quantities — so a marker assessing an AMA paper is judging more than your reference list. Second, AMA expects tables and figures to be numbered and cited in order, much like references, and to be self-explanatory. You will not need the full depth of these rules for most coursework, but knowing they exist — and consulting the AMA Manual of Style when a module demands them — is part of writing competently in the style.

Quoting, page numbers and AMA's wider style

Direct quotation is used sparingly in medical writing, and AMA reflects that. Because the in-text citation is a superscript number, you do not normally give a page number in the text; where a specific page is needed for a direct quotation, AMA places it in the reference or, in some contexts, beside the citation. As in all the health-science styles, the convention is to paraphrase and synthesise evidence rather than quote it — a sentence summarising several studies, each with its superscript number, reads far better than a chain of quoted fragments, and it shows a marker that you have understood the literature rather than merely transcribed it.

It is worth remembering that AMA is a complete writing style, not only a citation system. The AMA Manual of Style sets out detailed rules for expressing numbers and units (it prefers SI units), for reporting statistics such as P values and confidence intervals, for abbreviations, and for the careful, person-first and unbiased language expected in clinical writing. You will not need the full depth of these rules for every assignment, but a marker assessing an AMA paper is judging more than your reference list: they are looking for writing that follows the conventions of the medical literature.

The practical takeaway is to treat AMA as two linked skills. The citation mechanics — superscript numbers in citation order, the first-three-then-et-al author rule, PubMed journal abbreviations — are what this guide focuses on, and a reference manager handles most of them. The writing conventions — units, statistics, restrained quotation, careful language — are learned by reading widely in the field and consulting the manual when a module demands them. Together they are what competent AMA-style writing looks like.

Common mistakes to avoid

• Using the Vancouver author rule (first 6) instead of AMA's (first 3 then "et al" for 7+).
• Listing references alphabetically rather than in citation order.
• Giving a source a new number each time instead of reusing its first number.
• Putting article titles in quotation marks or title case — AMA uses sentence case, no quotes.
• Writing journal names in full when PubMed abbreviations are required.
• Adding spaces or full stops in author initials ("Smith J. R.", should be "Smith JR").
• Forgetting the "Accessed [date]" element on web sources.

Five habits for accurate AMA

1. Cite with software from the first sentence. Superscript numbering is positional; insert citations as you write and let the tool maintain them.

2. Learn the author threshold. Up to six listed in full; seven or more, first three then "et al". This single rule trips up most newcomers from Vancouver.

3. Export from PubMed. It gives you the correct author format and journal abbreviation automatically — the two most error-prone parts of an AMA entry.

4. Keep titles in sentence case. No quotation marks, only the first word and proper nouns capitalised; the journal name abbreviated and italicised.

5. Verify the mapping. Before submitting, confirm each superscript points to the intended source and that no number in the text is missing from the list.

Grasp the superscript-in-citation-order principle, remember AMA's distinctive author threshold, and let software handle the renumbering and abbreviations, and AMA becomes a quick, compact style to write in. When clinical study leaves no time for the reference list, our health-sciences writers will produce a fully AMA-formatted paper.

Frequently asked questions

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