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:

1. In-text citations — Superscript numbers

2. 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 placed after punctuation (except for dashes and parentheses).

Basic Citation

The treatment showed significant improvement in patient outcomes.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 previously noted,¹ the treatment protocol requires modification.

Author Named in Text

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

Chen et al³ demonstrated that early intervention improves outcomes.

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

1. Shapiro MF, Hayward RA. Equity and quality: new findings in the US health care system. JAMA. 2019;321(12):1153-1154.

Journal Article with DOI

2. Chen L, Wang X, Liu Y. Novel therapeutic approaches in oncology. N Engl J Med. 2023;388(15):1402-1415. doi:10.1056/NEJMra2215847

Journal Article (More Than 6 Authors)

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

3. Smith AB, Jones CD, Williams EF, et al. Cardiovascular outcomes in diabetic patients. Circulation. 2022;145(8):612-623.

Book

4. Goodman LS, Gilman A. Goodman and Gilman's The Pharmacological Basis of Therapeutics. 13th ed. McGraw-Hill Education; 2018.

Chapter in Book

5. Meltzer PS, Kallioniemi A. Chromosome alterations in solid tumors. In: Vogelstein B, Kinzler KW, eds. The Genetic Basis of Human Cancer. 2nd ed. McGraw-Hill; 2002:93-113.

Website

6. World Health Organization. Mental health. Accessed March 15, 2024. https://www.who.int/health-topics/mental-health

Online Newspaper/Magazine

7. Kolata G. A new drug shows promise for Alzheimer's patients. New York Times. January 5, 2023. Accessed February 10, 2024. https://www.nytimes.com/2023/01/05/health/alzheimers-drug.html

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)

No issue number for continuous pagination — If a journal uses continuous pagination throughout a volume, omit the issue number

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:

Further Resources

• AMA Manual of Style Online — Official subscription resource

• AMA Style Insider Blog — Updates and tips from AMA editors

• NLM Citing Medicine — Free comprehensive guide

Need help generating AMA citations? Research tools like Wonders can export your sources in AMA format automatically.