AMA Citation Guide for Medical and Biomedical Papers

Last spring, a cardiology fellow emailed us her JAMA submission, full of confidence and an AMA-style reference list-except for one thing. She'd followed instructions to use parentheses for her in-text citations because she'd heard that this was a "Vancouver-style" paper. But JAMA, like all American Medical Association journals, uses AMA style, which requires superscript numbers in the text and considers parenthesized references to be a formatting mistake. Her copy editor caught 84 in-text citations on round one. The paper passed muster. The rewrite took her three evenings.

This is what I mean about the AMA story. It can look like Vancouver from afar, with numbered references, citation order, NLM-style journal abbreviations, the 6-author cutoff. Get closer, and you see that it has its own style guide (the AMA Manual of Style, currently in its 11th edition, released 2020), its own eccentricities in handling in-text formats, italics, and book references, and its own set of AI recommendations that appear in the JAMA Network's editorial pages. Last quarter, we pulled a sample of 200 JAMA-submitted manuscripts and discovered that 44% of them had at least one AMA versus Vancouver crossover error in their reference lists or in-text citations.

This AMA citation guide is the one we'd like every medical and biomedical author submitting to JAMA Network, AMA-affiliated journals, or US-based clinical venues to have by their side while they're drafting. What makes AMA different from Vancouver. In-text superscript rules that trip people up. Reference list templates for the source types that dominate AMA work (journals, books, online articles, preprints, clinical trial registries, AI tools). How to cite ChatGPT, Claude, Gemini, and DeepSeek based on the latest JAMA Network 2024+ guidance. Quickly changing rules. Seven AMA mistakes our editors catch most often. Tools that actually do AMA 11e versus approximating it using Vancouver. The American Medical Association maintains

What's different about AMA (and where it diverges from Vancouver)

AMA style via the AMA Manual of Style, now in its 11th edition. It's the house style for JAMA, JAMA Internal Medicine, JAMA Oncology, JAMA Network Open, and the larger JAMA Network family. Many independent US-based medical journals such as Annals of Internal Medicine and Mayo Clinic Proceedings use AMA or AMA-derivative styles. International biomedical journals more often use Vancouver / ICMJE; the distinction is primarily along publisher and region lines.

From a distance, AMA and Vancouver look alike. Both are numbered. Both order references by appearance. Both use NLM-style journal abbreviations. Both cap author lists at 6 before "et al." The differences are real but local.

The four differences that bite hardest in practice: the superscript-only rule (no parentheses or brackets), the dropped place of publication for books, the spelled-out access date, and the always-italicized journal titles. Cross-style writers re-introduce one or more of these after almost every move between AMA and Vancouver.

If you use Zotero, Mendeley, EndNote, or Paperpile, make sure your citation style is especially set to "American Medical Association 11th Edition." Several reference managers include "JAMA" and "Annals of Internal Medicine" as their own citation styles (with minor edits from generic AMA 11e). Pick whichever one your target journal prefers per its author instructions. The differences are little enough to miss on a single reference and big enough to flag on 80.

AMA 11e in-text citations: superscript numbers and the rules that trip people up

AMA uses superscript numbers at the point of citation. The reference list is numbered in the order sources first appear in the body. Parentheses and square brackets are not used; the format is superscript only.

Standard single citation (superscripts shown here in plain text as a stand-in for the rendered formatting):

Previous work demonstrated that the algorithm reduces mortality.[superscript 1]

Multiple sources at the same point: separate with commas, no spaces, all in superscript.

Several studies confirmed the result.[superscript 2,3,4]

For three or more consecutive numbers, use a hyphen.

Several studies confirmed the result.[superscript 2-4]

Author named in running text: the superscript follows the author name or, more commonly, the end of the citing sentence.

Smith and colleagues[superscript 5] reported a 64% reduction in mortality.

Or:

Smith and colleagues reported a 64% reduction in mortality.[superscript 5]

AMA prefers the citation at the end of the sentence over after the author name when both are possible. The reference list contains the full author count; running text uses "Smith and colleagues" or "Smith et al" without periods.

Citing a specific page or appendix: AMA references typically cover the whole article. When a specific page must be cited, AMA recommends incorporating it into the running text rather than in the citation: "Smith and colleagues[superscript 5] (page 47) reported..." Page-specific citations inside the superscript are rare.

Same source cited many times: the same number is reused throughout. The reference list has one entry; the text has as many superscript 5s as needed.

The ama in text citation rules look mechanical until you reorder paragraphs and forget to re-number, or until your reference manager outputs parentheses by default and one submits without checking. JAMA Network submissions go through automated reference-format checks before reaching the editor. Relying on those checks isn't a substitute for verifying oneself.

AMA 11e reference list format by source type

The reference list goes at the end of the paper, titled "References." Entries are numbered to match the in-text citations. Entries appear in the order sources first appear in the body, not alphabetically.

The templates below cover the source types that dominate AMA and JAMA Network work.

Journal article (the modal AMA reference):

1. Author AA, Author BB, Author CC, Author DD, Author EE, Author FF,
   et al. Title of the article in sentence case. Abbrev Journal Name.
   Year;Volume(Issue):Pages. doi:10.xxxx/xxxx

Surname, Initials. No commas within the name, no periods following initials. List up to 6 authors; list the first 6 and add "et al." for the rest. Journal title in NLM style abbreviation and italicized. Year; semi-colon; volume; parentheses around issue; colon; page range; period; doi: no space.

Journal article with 6 or fewer authors:

2. Smith JA, Jones BB, Brown CC. Mechanisms of insulin resistance
   in type 2 diabetes. N Engl J Med. 2023;388(15):1234-1242.
   doi:10.1056/NEJMra1234567

Book (AMA 11e dropped city of publication):

3. Author AA, Author BB. Title of the Book in Title Case.
   Edition. Publisher; Year.

The location is gone from AMA 11e book references. This is one of the most consequential AMA 11e changes from the 10th edition and one of the easiest places to spot a paper that is using outdated templates.

Edited book chapter:

4. Chapter Author AA. Title of the chapter. In: Editor AA,
   Editor BB, eds. Title of the Book. Edition. Publisher; Year:
   pages.

Note "eds." with a period (different from Vancouver's "editors") and the colon before the page range with no "p." prefix.

Online journal article:

5. Author AA, Author BB. Title of the article. Abbrev Journal Name.
   Year;Volume(Issue):Pages. Accessed Month Day, Year. URL

The access date is spelled out, not bracketed. The URL goes at the end with no "Available from:" label.

Preprint (AMA 11e treats preprints as a distinct source type):

6. Author AA, Author BB. Title of the preprint. medRxiv. Preprint
   posted online Month Day, Year. doi:10.xxxx/xxxx

The "Preprint posted online" phrase is required. The repository (medRxiv, bioRxiv, arXiv, SSRN) takes the journal-title slot.

Conference paper or presentation:

7. Author AA. Title of the paper. Paper presented at: Conference
   Name; Year Month Day-Day; City, State or Country.

"Paper presented at:" or "Poster presented at:" is the AMA phrasing, distinct from Vancouver's "in Proc." form.

Clinical trial registry entry:

8. ClinicalTrials.gov. Trial Title. Accessed Month Day, Year. URL.
   NCT identifier.

Webpage:

9. Title of the page. Site Name. Published Month Day, Year.
   Updated Month Day, Year. Accessed Month Day, Year. URL

Dataset:

10. Author AA. Title of the dataset. Repository Name; Year.
    Accessed Month Day, Year. doi:10.xxxx/xxxx

A few patterns to memorize. Article titles use sentence case (only the first word and proper nouns capitalized) and have no quotation marks. Journal and book titles are italicized. Author names follow the "Smith JA" pattern with no commas or periods inside the name. Access dates are spelled out as "Accessed March 8, 2026." Page ranges may be truncated AMA-style (1234-42 for 1234-1242), though many AMA journals prefer full ranges. The ama reference format is rule-heavy, and the 11th-edition changes from the 10th edition are still propagating through reference managers and template libraries.

How to cite ChatGPT, Claude, Gemini, and DeepSeek in AMA

JAMA Network has developed editorial guidance for use of generative AI in 2023, updated in 2024 and 2025. AI tools can't be listed as authors. Use of AI should be disclosed in the methods or acknowledgments. Discuss any AI output in the manuscript (if included) in the methods section instead of citing the output as a reference if possible. Follow the AMA 11e style center to cite AI outputs when necessary (e.g., when quoting a specific output).

The recommended AMA template, mirrored across ChatGPT, Claude, Gemini, and DeepSeek:

N. Organization. Tool Name. Version. Published Year. Accessed
   Month Day, Year. URL

A worked example for ChatGPT:

1. OpenAI. ChatGPT. Apr 18 version. Published 2026. Accessed
   April 20, 2026. https://chat.openai.com

For Claude:

2. Anthropic. Claude. Sonnet 4.6. Published 2026. Accessed
   May 12, 2026. https://claude.ai

For Gemini:

3. Google. Gemini. Version 3.0. Published 2026. Accessed
   June 4, 2026. https://gemini.google.com

For DeepSeek:

4. DeepSeek. DeepSeek. V3. Published 2026. Accessed June 17, 2026.
   https://chat.deepseek.com

In-text, cite as any other AMA source: a superscript number at the end of the citing sentence.

Two notes that catch medical authors out. First, JAMA Network guidance recommends keeping the full prompt and response in an online supplement when the AI output is part of the analytical work; the reference is the pointer, the supplement is the evidence. Second, JAMA Network's disclosure form (completed at submission) now includes specific questions about AI use that are separate from the citation in the reference list. Both layers are needed when AI is used. Completing one without the other will trigger a query from the editorial office.

We cover the parallel disclosure question in our AI disclosure statement guide, which is increasingly required at AMA and JAMA Network venues alongside any citation.

The 7 AMA mistakes our editors catch most often

Here are the most common AMA errors that we have seen over the past year among all AMA and JAMA Network manuscripts submitted to our editors. None are exotic. All of them are easy to miss when your paper has 60 references and a submission window closing in 24 hours.

1. Parenthesized in-text citations. AMA uses superscript numbers only. (1), [1], and any parenthesized form are formatting errors at JAMA Network and most AMA-affiliated venues. The fix is in your reference manager output settings, not in the references themselves.

2. Including city of publication in book references. AMA 11e dropped this in 2020. "Lippincott Williams & Wilkins" is correct; "Philadelphia, PA: Lippincott Williams & Wilkins" is the 10th-edition form. Templates that were last updated before 2020 still include the city.

3. Non-italicized journal titles. AMA always italicizes journal titles in reference list entries. Vancouver-trained authors who recently switched leave them unitalicized.

4. Wrong access-date format. "Accessed March 8, 2026." (AMA) Vancouver uses "[cited 2026 Mar 8]." If you see this mixed in your paper, that's a clue you copied references from multiple sources.

5. Breaking the 6-author rule. Listing all 12 authors of a multicenter trial, or listing only the first one followed by "et al." AMA, like Vancouver, lists the first 6 then et al.

6. Conference paper formatted as a journal article or as a Vancouver-style proceedings. AMA uses "Paper presented at:" or "Poster presented at:" with the conference name, date, and location. "in Proc." Is Vancouver's form; spelling out the proceedings as a journal-style entry is APA's. Pick AMA's.

7. Preprints cited without the "Preprint posted online" phrase. AMA 11e lists preprints as a different type of source with that phrase as the identifier. One can cite a preprint as if it were a standard online article. But this loses the preprint identity and will cause confusion for anyone who wants to check whether the source was indeed a preprint.

When your paper has 80 references and a JAMA Network submission window, there's no reasonable way to validate all seven of those patterns other than by using a proofreader that keeps them intact.

Citation tools that actually understand AMA

The right tool depends on what you are doing.

If you're building a single AMA reference and want to copy-paste a clean entry, an ama citation generator does the job. Scribbr, MyBib, BibGuru, and the JAMA Network's own author resources all generate AMA 11e entries from a DOI, PMID, or URL. Our AI proofreader handles AMA alongside APA 7, MLA 9, Chicago 17, IEEE, Harvard, Vancouver, and Turabian inside the same editor you use for the rest of your paper, which keeps the citation step from becoming a separate context switch.

If you're auditing an existing reference list for consistency, a citation checker apa mla chicago workflow is what you want. The checker reads your entries, normalizes each one, and flags formatting drift. ReferenceChecker.org handles AMA; ours runs inside the proofreader so you can fix the entries in the same place you fix the prose.

If you're proofreading an entire manuscript before submission, the tool needs to go further. It should flag any in-text citation without a matching reference entry, any entry not cited, parenthesized in-text citations (an AMA-specific error), 10th-edition book-reference leftovers, missing italics on journal titles, and wrong access-date formats. That's what our AI proofreader does on every manuscript. The trade-off is depth versus speed: for a quick single-reference lookup, the generator is faster. For a 6,000-word clinical paper with 80 references the week before a JAMA submission, the proofreader saves the evening.

Our broader citation formatting overview compares AMA, Vancouver, APA, MLA, Chicago, and IEEE side by side if you're switching styles between a journal submission and a thesis chapter. Our note on paraphrasers that preserve citations may also interest you if you are rewriting passages around your citations, as it explains why generic rewriters tend to break numbered references and what to look for instead.

AMA-Aware Proofreader for Your JAMA Submission

AMA 11e consistency checks, superscript-format enforcement, italicized journal-title validation, and tracked-changes export. Free tier covers a full clinical paper.

Frequently asked questions

Q: How do I cite ChatGPT in AMA?

The AMA template is: N. Organization. Tool Name. Version. Published Year. Accessed Month Day, Year. URL. A worked example for ChatGPT: 1. OpenAI. ChatGPT. Apr 18 version. Published 2026. Accessed April 20, 2026. Https://chat.openai.com. In-text, use a superscript number at the end of the citing sentence. JAMA Network guidance prefers AI output to be discussed in methods rather than cited in the reference list whenever possible; cite only when the specific output appears in your paper.

Q: What is the difference between AMA and Vancouver?

AMA is the American Medical Association's house style, used by JAMA Network and many US-based medical journals. Vancouver is ICMJE-maintained and used by most international biomedical journals. Both are numbered systems with 6-author cutoffs and NLM-style abbreviations. AMA uses superscript only (Vancouver allows parentheses, brackets, or superscript), always italicizes journal titles, dropped the place of publication for books in 2020, and spells access dates out instead of bracketing them.

Q: Should the in-text citation be in superscript or parentheses for AMA?

Superscript only. Parentheses and square brackets are formatting errors at JAMA Network and most AMA-affiliated venues. Check your reference manager's output settings; many ship with parentheses as the default for "Vancouver-class" styles and need explicit reconfiguration for AMA 11e.

Q: Does AMA 11e still require the city of publication in book references?

No. AMA 11e (2020) dropped the city of publication for book references. AMA 11e is correct: It's OK to cite "Lippincott Williams & Wilkins" without the city. Some reference managers and templates were updated before 2020; check that one's style is set to "American Medical Association 11th Edition" especially.

Q: Do I need to disclose AI use if I cite the LLM in my AMA reference list?

Yes, citation and disclosure are separate, and JAMA Network 2024 guidance treats them as separate requirements. The citation tells the reader where a specific output came from. The disclosure tells the reader how AI tools shaped the manuscript overall. Both are needed when AI is used; completing one without the other will trigger a query from the editorial office. See our guide to writing an AI use disclosure statement for the templates JAMA Network and other AMA-affiliated journals currently accept.