AMA Citation Style — Complete Guide

AMA citation style — overview

AMA (American Medical Association) style is the citation format used by JAMA (Journal of the American Medical Association) and many other medical and health science publications. It is also required by numerous North American medical and nursing schools. The current edition is the 11th (2020).

AMA uses a numbered superscript system: each source is assigned a superscript number in the text, and full citations appear in a numbered reference list. Like Vancouver, sources are numbered in order of first citation — not alphabetically.

AMA vs Vancouver — key differences

In practice, AMA and Vancouver are very similar. The most notable AMA difference is that initials have no spaces or periods between them: "SmithAB" not "Smith AB". Also, AMA uses et al. for 4+ authors (not 7+).

In-text citations

AMA uses superscript numbers placed after the relevant text — after punctuation at the end of a sentence, or within a sentence at the point of citation:

Reference list rules

• Title the page References
• Number entries in the order of first citation in the text — NOT alphabetical
• Author initials: no spaces, no periods — "SmithAB" or "Smith AB" (AMA 11th uses no space)
• Up to 3 authors: list all. 4 or more: list first 3, then "et al."
• Journal names: abbreviated using NLM abbreviations, italicised
• Article titles: sentence case, no quotation marks, no italics
• Year;Volume(Issue):Pages — semicolon after year, colon before pages
• Include DOI where available

Journal article

Book

Chapter in edited book

Website

Author name rules in AMA

• Surname followed by initials with NO spaces and NO periods: "SmithAB" — this is the most distinctive AMA feature
• Multiple authors separated by commas
• 3 or fewer: all listed. 4 or more: first 3, then "et al."
• Organisation as author: spell out the full name (not an acronym unless the acronym is the official name)
• No author: start with the title of the work

Common AMA mistakes

• Adding spaces or periods to author initials — AMA uses "SmithAB" not "Smith, A.B." or "Smith AB"
• Using et al. for 3 or fewer authors — only use for 4+ (unlike Vancouver which uses it for 7+)
• Alphabetising the reference list — AMA is numbered in order of first citation
• Writing journal names in full — AMA uses NLM abbreviated, italicised forms
• Using the wrong punctuation structure: Year;Volume(Issue):Pages — the semicolons and colon placement is precise