The American Medical Association citation format uses numbered superscript references and a compact reference list. Standard for nursing, medicine, public health, and allied health dissertations — and used by thousands of medical journals worldwide.
AMA citation style is published by the American Medical Association and is now in its 11th edition. It is the dominant citation format in medical and health sciences, required by journals including JAMA, Annals of Internal Medicine, JAMA Network titles, and many others. It is also the required style for nursing, public health, and allied health dissertations at many programmes.
AMA uses a numbered citation system: references are assigned numbers in the order they first appear in the text, and those same numbers appear as superscripts throughout the paper. The reference list at the end is ordered numerically — not alphabetically — matching the order sources were first cited.
This number-based system differs fundamentally from author-date systems like APA, Harvard, or Vancouver. The advantage is that readers can immediately locate the full source using the number; the disadvantage is that inserting a new source mid-paper requires renumbering everything after it.
Both AMA and Vancouver use numbered superscript citations and numeric reference lists. Students frequently ask which is which:
| Feature | AMA (11th ed.) | Vancouver |
|---|---|---|
| Publisher | American Medical Association | International Committee of Medical Journal Editors (ICMJE) |
| In-text format | Superscript ¹²³ | Superscript ¹²³ or (1)(2)(3) |
| Author names | Last FM (initials, no periods) | Last FM (initials, no periods) |
| Author list cutoff | Up to 6; then "et al." | Up to 6; then "et al." |
| Journal title | Abbreviated (no periods) | Abbreviated (no periods) |
| Volume/issue format | Year;Vol(No):pages | Year;Vol(No):pages |
| DOI format | doi:10.xxxx/xxx (no URL prefix) | https://doi.org/10.xxxx/xxx |
In practice the two styles are nearly identical. AMA has more precise formatting rules around abbreviations and punctuation. If your module specifies "Vancouver," see our Vancouver guide.
Superscript numbers appear at the point of citation, placed after any punctuation mark:
After punctuation: superscript numbers follow the period or comma — "The incidence increased dramatically.¹" The number sits after the period. This is the opposite of what most word processors auto-place, so manually check each citation before submitting.
Journal articles are the most common source type in medical writing. The format is compact and highly standardised.
Health sciences dissertation specialists who know AMA 11th edition — nursing, medicine, public health.
Avoid citing websites when a peer-reviewed source is available for the same information. When you must cite a website, include the organisation, title, URL, publication/update date, and access date.
| Full Journal Name | NLM Abbreviation |
|---|---|
| New England Journal of Medicine | N Engl J Med |
| Journal of the American Medical Association | JAMA |
| The Lancet | Lancet |
| Annals of Internal Medicine | Ann Intern Med |
| BMJ (British Medical Journal) | BMJ |
| Nature Medicine | Nat Med |
| PLOS Medicine | PLoS Med |
| American Journal of Nursing | Am J Nurs |
| Journal of Clinical Oncology | J Clin Oncol |
| Archives of Internal Medicine | Arch Intern Med |
Find any abbreviation: Use the NLM Catalog at ncbi.nlm.nih.gov/nlmcatalog — search the journal name and check the Abbreviation field. Zotero, Mendeley, and EndNote all auto-fill NLM abbreviations when you import citations from PubMed.
Use a hyphen for consecutive references: ¹⁻³ means references 1, 2, and 3 in sequence. Use a comma (displayed as an apostrophe in superscript) to separate non-consecutive references: ¹'⁴'⁷ means references 1, 4, and 7. Do not write the word "through" — the hyphen is sufficient.
Include a DOI whenever one is available — AMA 11th edition strongly recommends it for all journal articles and book chapters. If there is no DOI, include a URL if the article is freely accessible online. For print-only articles, no URL is needed.
List the first three authors, then add "et al." with a period: Chen JK, Patel RM, Torres LD, et al. This applies when there are seven or more authors. For exactly six, list all six without "et al."
Yes — strongly recommended. Zotero, Mendeley, and EndNote all have AMA citation styles built in. They autofill journal abbreviations, handle author formatting, and automatically renumber citations when you insert or delete references. Manual renumbering in a 50-reference paper is a significant source of errors.
NLM (National Library of Medicine) style and AMA style are very closely related — AMA is based on NLM/ICMJE conventions. NLM style is used by PubMed and most MEDLINE-indexed references. The practical differences are minor; AMA adds specific formatting rules for books and grey literature. If your institution uses "NLM style," following AMA 11th edition is a safe and thorough approach.