How do you cite in AMA format?

Number each source in the order you first cite it and put that number in superscript in the text, after periods and commas. In the reference list, write: Author AB, Author CD. Title of article in sentence case. Abbreviated Journal Name. Year;Volume(Issue):Pages. doi. Reuse the same number whenever you cite that source again.

How do you cite a website in AMA format?

Author or organization. Title of the page. Name of the website. Published date. Updated date. Accessed date. URL. Leave out any element that is not available; the accessed date and URL are always needed. Example: World Health Organization. Mental health. Accessed September 21, 2026. https://www.who.int/health-topics/mental-health

Are reference numbers superscript or in brackets?

Superscript. Place the number after periods and commas and before colons and semicolons: “...previous studies reported similar findings.¹” Some journals use parentheses or brackets instead, but superscript is standard AMA.

Do I include article titles in references?

Yes. Unlike some numbered styles, AMA requires article titles for journal references. Capitalize only the first word and proper nouns (sentence case).

What's the difference between AMA and Vancouver?

Both are numbered styles for medical literature, but AMA (American Medical Association) is used primarily in US medical journals, while Vancouver (ICMJE) is the international standard. Formatting details differ slightly—always check which your target journal requires.

How many authors do I list?

List all authors up to 6. For 7 or more, list the first 3 followed by “et al.” This is different from other styles, so verify the exact cutoff if you're near the threshold.

How do I cite online-only journals?

Include the DOI at the end: doi:10.xxxx/xxxxx. If no DOI is available, provide the URL and access date. For ePub ahead of print, include “Published online [date]. doi:...”

AMA Manual of Style 11th Edition: JAMA Reference Format

AMA format at a glance

In the text: a superscript number, assigned in order of first citation.

A two-dose regimen of BNT162b2 was 95% effective at preventing Covid-19 in the pivotal efficacy trial.¹

In the reference list: numbered entries in the same order.

Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020;383(27):2603-2615. doi:10.1056/NEJMoa2034577

Source	AMA reference format
Journal article	Author AB, Author CD. Title of article. Abbrev Journal Name. Year;Volume(Issue):Pages. doi:xx
Book	Author AB. Title of Book. Edition. Publisher; Year.
Book chapter	Author AB. Title of chapter. In: Editor AB, ed. Title of Book. Edition. Publisher; Year:Pages.
Website	Author or Organization. Title of page. Website Name. Published date. Updated date. Accessed date. URL

Number of authors	What to list
1 to 6	All authors
7 or more	First 3, then et al

The Official Source

The AMA Manual of Style: A Guide for Authors and Editors, 11th Edition (2020) is published by Oxford University Press and written by the editors of JAMA and the JAMA Network journals. Access the online version at amamanualofstyle.com.

The 11th edition includes expanded guidance on data sharing, research ethics, inclusive language, and citing digital sources including social media.

Quick Overview

AMA uses a numbered citation system:

In-text citations — Superscript numbers
Reference list — Numbered entries in order of first citation

References are numbered consecutively as they appear in your text—not alphabetically.

In-Text Citations

Use superscript Arabic numerals. Place them after periods and commas, and before colons and semicolons.

Basic Citation

A two-dose regimen of BNT162b2 was 95% effective at preventing Covid-19.¹

Multiple Sources

Separate with commas; use a hyphen for consecutive numbers.

Several studies have confirmed these findings.¹,³,⁷
This approach has been widely validated.²⁻⁵

Citing the Same Source Again

When you cite a source again, use its original number.

As noted earlier,¹ the trial reported 95% efficacy.

Author Named in Text

You may mention the author's name, but still include the superscript number.

Halpern et al³ discuss solid-organ transplantation in patients with HIV.

Every source used as an example on this page is a real, published work; the superscript numbers are illustrative.

Reference List Basics

The reference list is titled "References" and numbered consecutively in order of first citation. Each entry begins with the reference number followed by a period.

Basic Structure

#. Author(s). Title of article. Journal Name Abbreviated. Year;Volume(Issue):Pages. doi:

Journal Article

Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002;347(4):284-287.

Journal Article with DOI

LeCun Y, Bengio Y, Hinton G. Deep learning. Nature. 2015;521(7553):436-444. doi:10.1038/nature14539

Journal Article (More Than 6 Authors)

List the first three authors followed by "et al."

Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020;383(27):2603-2615. doi:10.1056/NEJMoa2034577

Book

Murray PR, Rosenthal KS, Kobayashi GS, Pfaller MA. Medical Microbiology. 4th ed. Mosby; 2002.

Chapter in Book

Meltzer PS, Kallioniemi A, Trent JM. Chromosome alterations in human solid tumors. In: Vogelstein B, Kinzler KW, eds. The Genetic Basis of Human Cancer. McGraw-Hill; 2002:93-113.

The book and chapter above are the works used in the National Library of Medicine's own sample references; the punctuation here follows AMA rather than NLM.

Website

World Health Organization. Mental health. Accessed September 21, 2026. https://www.who.int/health-topics/mental-health

Online Newspaper/Magazine

Author AB. Title of article. Name of Newspaper. Month Day, Year. Accessed Month Day, Year. URL

Key AMA Conventions

Author names — List surname first, followed by initials without periods: Smith AB (not Smith, A. B.)
Journal abbreviations — Use standard NLM/MEDLINE abbreviations (e.g., N Engl J Med, JAMA, Lancet)
Volume and issue — Year;Volume(Issue):Pages with no spaces: 2020;383(27):2603-2615
Page ranges — Write both numbers in full (284-287), unlike Vancouver, which shortens them (284-7)
DOIs — Include when available, without "https://doi.org/" prefix: doi:10.xxxx/xxxxx
Accessed dates — Required for online sources
Et al. — Use after three authors when there are more than six total authors

Common Mistakes to Avoid

Alphabetizing references — AMA references are numbered by citation order, not alphabetically.
Using full author names — Use initials only: Smith AB, not Smith, Andrew B.
Periods in initials — No periods between initials: Smith AB (not Smith A.B.)
Wrong journal abbreviations — Use NLM standard abbreviations. Check PubMed for correct forms.
Missing access dates — Online sources require "Accessed [Date]."
Including "pp." for page numbers — AMA doesn't use "pp." before page ranges.

11th Edition Updates

Key changes in the 2020 edition:

Singular "they" — Now accepted for referring to individuals whose gender is unknown
Patient-first language — Emphasis on inclusive, person-centered terminology
Data sharing — New guidance on citing datasets and repositories
Social media citations — Updated formats for tweets, posts, and online content
Research ethics — Expanded coverage of conflicts of interest and publication ethics
Race and ethnicity — Updated guidance on appropriate terminology

Who Uses AMA Style?

AMA is the standard for:

Medical journals (especially JAMA Network)
Health sciences research
Nursing journals
Biomedical publications
Clinical research reports
Medical school coursework

If you're submitting to a medical journal or studying in health sciences, check whether the publication uses AMA or Vancouver style.

AMA vs. Vancouver

Both are numbered systems used in medicine, but they differ in formatting details:

Element	AMA	Vancouver
In-text format	Superscript	Parentheses or superscript
Author format	Smith AB	Smith AB.
Journal title	Italicized	Not italicized
"et al." threshold	After 3 of 6+ authors	After 6 authors

Further Resources

AMA Manual of Style, 11th edition (Oxford University Press): the official source; chapter 3 covers references. Subscription required
AMA Style Insider: updates and tips from the manual's editors
NLM Catalog: journal title abbreviations

Accessed 21 September 2026.

Wonders helps you find and organize papers, then exports your library as RIS or BibTeX or sends it to Zotero, where the AMA 11th edition style is available. It cannot output AMA itself — see what it does and does not do for nursing and health students.