Vancouver citation style: a complete guide
Vancouver is the numbered citation style used by the majority of biomedical journals — including those indexed in MEDLINE and PubMed. It was developed by the International Committee of Medical Journal Editors (ICMJE) and is closely aligned with the U.S. National Library of Medicine (NLM) reference format. If you write for a clinical or biomedical journal, our free citation generator formats Vancouver references — with the correct journal abbreviation — in seconds.
What is Vancouver style?
Vancouver style was created in 1978 at a meeting of medical journal editors in Vancouver, British Columbia. The group's recommendations evolved into the ICMJE document Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals, and the U.S. National Library of Medicine maintains the detailed reference formatting in Citing Medicine (the NLM style guide).
Most biomedical and clinical journals — The Lancet, the BMJ, the New England Journal of Medicine, the JAMA family, and thousands of smaller specialty titles — either follow Vancouver directly or use a close variant. If your target journal's instructions to authors mention "ICMJE references," "NLM format," or "uniform requirements," they are asking for Vancouver style.
The two defining features of Vancouver are:
- Numbered in-text citations. Sources are referenced by a number — usually in parentheses or as a superscript — assigned in the order they first appear in the text.
- A reference list in citation order. The reference list is numbered to match, so reference 1 is the first source cited, reference 2 is the second new source, and so on. It is not alphabetical.
In-text citation numbers
Each source is assigned a number the first time it is cited; that number is reused every subsequent time the same source appears. The most common formats are Arabic numerals in parentheses or square brackets, or as a superscript without brackets. Always check your target journal's instructions — the choice between (1), [1], and 1 is the journal's call.
Statin therapy reduces cardiovascular events in adults with type 2 diabetes (1,2).
Statin therapy reduces cardiovascular events in adults with type 2 diabetes.1,2
Multiple sources in one citation
When citing more than one source at the same point, list the numbers separated by commas with no spaces. For three or more consecutive numbers, use an en dash to indicate a range.
Several systematic reviews have reached the same conclusion (3–6,9).
Citing the author by name
When you mention the author in running text, the citation number follows the name immediately — not the end of the sentence. The number still represents the same reference list entry.
Patel et al. (7) found a 32% reduction in 30-day readmissions among patients receiving the intervention.
Position relative to punctuation
Vancouver places the citation number before any
punctuation when it is in parentheses or brackets — for example,
… as expected (3). When superscripts are used, most
journals (NEJM, Nature Medicine) place them after
punctuation. Follow the journal's published style.
Reference list rules
The reference list appears at the end of the manuscript under the heading References. Entries are numbered in the order the sources first appear in the text — not alphabetically. Each entry begins with the citation number, followed by the bibliographic details.
Author names
List authors as Last name + initials with no periods: Smith JA, not Smith, J. A. Separate authors with commas. List the first six authors, then add "et al." if there are seven or more. (Some journals require the first three only — always check the target journal.)
One author: Smith JA.
Two authors: Smith JA, Jones BC.
Six authors: Smith JA, Jones BC, Williams DE, Brown AF, Taylor GH, Lee KL.
Seven or more: Smith JA, Jones BC, Williams DE, Brown AF, Taylor GH, Lee KL, et al.
Title case
Article and chapter titles use sentence case — only the first word and proper nouns are capitalized. Journal names are abbreviated and not italicized in classic Vancouver, though many journals now italicize them for readability.
Year, volume, issue, pages
After the journal abbreviation, give the year, volume, issue (in
parentheses), and page range. The format is compact:
2023;48(3):145–52. Page ranges are abbreviated — for
example, 145–52 rather than 145–152, since the prefix digits repeat.
Journal articles
Journal articles are the dominant source type in biomedical writing. The standard Vancouver/NLM format is:
Author AA, Author BB, Author CC. Title of article. Journal Abbrev. Year;Volume(Issue):pages. doi:10.xxxx/yyyyy
1. Patel V, Saxena S, Lund C. Mental health systems in countries: where are we now? Lancet. 2018;392(10157):1553–98. doi:10.1016/S0140-6736(18)31612-X
2. Bhatt DL, Steg PG, Miller M, Brinton EA, Jacobson TA, Ketchum SB, et al. Cardiovascular risk reduction with icosapent ethyl for hypertriglyceridemia. N Engl J Med. 2019;380(1):11–22. doi:10.1056/NEJMoa1812792
Articles with a DOI but no print issue
For articles published online ahead of print, append "Online ahead of print." after the journal abbreviation and date. Many journals also accept the format used by PubMed's "Epub" notation.
3. Chen L, Garcia M. Long-term outcomes of GLP-1 receptor agonists in nondiabetic obesity. JAMA Intern Med. Online ahead of print 2026 Feb 14. doi:10.1001/jamainternmed.2026.0123
Open-access and PMC identifiers
When citing an open-access article, the DOI is preferred. Some
journals also accept PubMed Central identifiers (PMCID:
PMC1234567) at the end of the entry, particularly for NIH-funded
work.
Journal name abbreviations
Vancouver style requires journal names to be abbreviated according to the NLM Title Abbreviations list (also called the Index Medicus abbreviations). These abbreviations follow strict rules:
- Single-word journal titles are not abbreviated (Lancet, Nature, Science).
- Common words are abbreviated to a standard form (Journal → J, Medicine → Med, Surgery → Surg).
- Periods are omitted after each abbreviation in modern Vancouver — write "N Engl J Med" rather than "N. Engl. J. Med."
- Articles, prepositions, and conjunctions ("of," "and," "the") are dropped.
| Full journal name | NLM abbreviation |
|---|---|
| New England Journal of Medicine | N Engl J Med |
| Journal of the American Medical Association | JAMA |
| British Medical Journal | BMJ |
| Annals of Internal Medicine | Ann Intern Med |
| Journal of Clinical Oncology | J Clin Oncol |
| American Journal of Public Health | Am J Public Health |
| Cochrane Database of Systematic Reviews | Cochrane Database Syst Rev |
| Proceedings of the National Academy of Sciences | Proc Natl Acad Sci U S A |
The full list is searchable at the NLM Catalog
(www.ncbi.nlm.nih.gov/nlmcatalog/journals) — every
MEDLINE-indexed journal has an official abbreviation. If the journal
you want to cite is not indexed in MEDLINE, write the title out in
full and apply standard NLM abbreviation rules.
Books and book chapters
Entire book
For an entire book, list the authors or editors, the title (sentence case), the edition (if not the first), the place of publication, the publisher, and the year. Unlike APA, Vancouver retains the place of publication.
Author AA. Title of book. Edition. Place of publication: Publisher; Year.
4. Goldman L, Schafer AI. Goldman-Cecil medicine. 26th ed. Philadelphia (PA): Elsevier; 2020.
5. Loscalzo J, Kasper DL, Longo DL, Fauci AS, Hauser SL, Jameson JL, editors. Harrison's principles of internal medicine. 21st ed. New York (NY): McGraw Hill; 2022.
Chapter in an edited book
For a chapter in an edited volume, list the chapter author, chapter title, then "In:" followed by the editor names and the book details and page range.
Author AA. Title of chapter. In: Editor EE, editor. Title of book. Edition. Place: Publisher; Year. p. xx–xx.
6. Murphy K. Innate immunity: the first lines of defense. In: Murphy K, Weaver C, editors. Janeway's immunobiology. 9th ed. New York (NY): Garland Science; 2017. p. 37–76.
Websites and online sources
For web pages, NLM/Vancouver requires the page title, the publisher or sponsoring organization, the date the page was published or last updated, the date you accessed it, and the URL. Web sources are used sparingly in clinical writing — peer-reviewed sources are strongly preferred — but agency reports, clinical guidelines, and registry pages often appear as references.
Author/Organization. Title of page [Internet]. Place: Publisher; Year [updated YYYY Mon DD; cited YYYY Mon DD]. Available from: URL
7. Centers for Disease Control and Prevention. Influenza (flu): clinical guidance for the prevention and treatment of influenza [Internet]. Atlanta (GA): CDC; 2024 [updated 2024 Sep 12; cited 2026 Apr 30]. Available from: https://www.cdc.gov/flu/professionals/treatment/clinical.htm
8. World Health Organization. WHO consolidated guidelines on tuberculosis: module 4: treatment [Internet]. Geneva: WHO; 2022 [cited 2026 Apr 30]. Available from: https://www.who.int/publications/i/item/9789240048126
Preprints and clinical trials
Preprints
Preprints (medRxiv, bioRxiv, arXiv) are increasingly cited in biomedical writing. Vancouver formats them like a journal article but identifies the server explicitly and notes "Preprint."
9. Williams JR, Tanaka H. Wastewater surveillance for emerging respiratory viruses: a multi-city pilot. medRxiv. Preprint posted 2026 Feb 3. doi:10.1101/2026.02.03.26271234
Clinical trial registry entries
When citing a registered trial protocol or status page, ClinicalTrials.gov entries are formatted as web sources with the trial registration number embedded.
10. National Institute of Allergy and Infectious Diseases. Phase 3 trial of a universal influenza vaccine [Internet]. Bethesda (MD): National Library of Medicine (US); 2024 [updated 2025 Nov 8; cited 2026 Apr 30]. ClinicalTrials.gov identifier: NCT05123456. Available from: https://clinicaltrials.gov/study/NCT05123456
Conference proceedings
Conference papers and abstracts are formatted similarly to journal articles. Note the conference name, location, and date.
11. Kumar S, Almeida R. Real-world outcomes of CAR-T therapy in relapsed lymphoma [abstract]. In: Proceedings of the American Society of Hematology Annual Meeting; 2025 Dec 6–9; San Diego (CA). Abstract no. 1234.
Vancouver vs. AMA
Both Vancouver and the AMA Manual of Style use numbered citations, and they look similar at a glance. The differences are subtle but consistent.
| Feature | Vancouver / NLM | AMA (11th ed.) |
|---|---|---|
| In-text format | (1), [1], or 1 — varies by journal | Always superscript1 |
| Author limit | List 6, then "et al." | List 6, then "et al." |
| Author name format | Smith JA (no periods, no commas) | Smith JA (no periods) |
| Journal name | NLM abbreviation, no periods, not italicized | NLM abbreviation, no periods, italicized |
| Article title case | Sentence case | Sentence case |
| Page range | Compact (145–52) | Compact (145-152, no en dash) |
| Volume/issue | 2023;48(3):145–52 | 2023;48(3):145-152 |
| DOI | doi:10.xxxx/yyyyy (no period at end) | doi:10.xxxx/yyyyy |
For a deeper look at AMA, see our AMA citation style guide.
Common mistakes to avoid
Alphabetizing the reference list
The reference list in Vancouver is in citation order, not alphabetical order. Reference 1 is the first source you cite; if you cite a different source first when you revise, every subsequent number shifts. Renumber carefully or use a reference manager.
Adding periods to journal abbreviations
Modern Vancouver drops periods. "N. Engl. J. Med." is incorrect; write "N Engl J Med" instead. The same goes for "JAMA" (no periods) and "BMJ" (no periods).
Including issue numbers when not needed
Some journals (and some style guides) only require the issue number when each issue restarts pagination at 1. If the journal paginates continuously through the volume, the issue is sometimes dropped. Check the target journal's instructions.
Inconsistent in-text format
Pick one in-text style — parentheses, brackets, or superscripts — and use it throughout the manuscript. Mixing (1) and 1 in the same paper is a frequent copyediting flag.
Title case in article titles
Article titles use sentence case. "Cardiovascular Risk Reduction With Icosapent Ethyl" is wrong; "Cardiovascular risk reduction with icosapent ethyl" is right. (The journal name itself stays in title case.)
Forgetting the DOI
Most biomedical journals now require a DOI in the reference whenever one exists. Our citation generator resolves DOIs automatically and produces the correct journal abbreviation, author format, and page-range style.
Quick summary
| Feature | Vancouver Rule |
|---|---|
| In-text format | Number in parentheses, brackets, or superscript — (1), [1], 1 |
| Reference list order | Citation order — not alphabetical |
| Author format | Last name + initials, no periods (Smith JA) |
| Author limit | List 6 authors, then "et al." |
| Article titles | Sentence case |
| Journal name | NLM abbreviation, no periods |
| Volume/issue/pages | Year;Vol(Issue):pages — e.g., 2023;48(3):145–52 |
| Place of publication (books) | Required: City (State): Publisher |
| DOI format | doi:10.xxxx/yyyyy |
| Web sources | Include [Internet], date accessed, full URL |
Vancouver style is more compact than APA or MLA, but it has its own strict rules — especially around journal abbreviations and citation-order numbering. Following the ICMJE Recommendations and the NLM Citing Medicine guide will keep your references compatible with virtually every biomedical journal.
Need a Vancouver-formatted reference quickly? Use CiteGenie's free citation generator — paste a DOI, PMID, or URL and get a Vancouver/NLM citation with the correct journal abbreviation in seconds.
Try the Citation Generator