Vancouver Style for Medicine 2026: Complete Citation Guide (ICMJE Recommendations)

The Vancouver style is the dominant citation standard for medical and biomedical writing worldwide. Maintained by the International Committee of Medical Journal Editors (ICMJE), it governs citations in major medical journals (The Lancet, NEJM, BMJ, JAMA) and the PubMed database. This guide covers Vancouver citation rules with examples by source type, as updated in the ICMJE Recommendations 2024 (current edition in 2026).

This is the authoritative practitioner reference, checked against the official ICMJE Recommendations (https://www.icmje.org/recommendations/) and the NLM (National Library of Medicine) citation guide.

What Vancouver Style Is, and When to Use It

The Vancouver style takes its name from a 1978 meeting of medical journal editors in Vancouver, British Columbia, where the original uniform requirements were agreed. The style is now maintained by the ICMJE (International Committee of Medical Journal Editors), updated annually, and applied by thousands of medical and biomedical journals.

Official source: https://www.icmje.org/recommendations/
NLM practical guide: https://www.nlm.nih.gov/bsd/uniform_requirements.html
Citing Medicine (free, NLM 2007): detailed reference for complex cases (https://www.ncbi.nlm.nih.gov/books/NBK7256/)

Current ICMJE version verified for this guide: ICMJE Recommendations 2024 (updated annually each January).

Disciplines using Vancouver:

• Medicine (internal, surgery, family medicine, all specialties)
• Biomedical research
• Dentistry
• Pharmacy and pharmacology
• Nursing research (sometimes; APA 7 also common)
• Veterinary medicine
• Public health
• Allied health sciences in many countries

Vancouver is the international standard for medical publication. In the US, AMA 11 (American Medical Association Manual of Style) is a Vancouver-adjacent variant with US-specific conventions. For full coverage of style variants, see our academic style guides reference.

Core Vancouver Rules

The Vancouver style has a few core conventions that distinguish it from APA, MLA and Chicago.

In-text citations: numerical, in order of appearance

Citations in the text use numbers (in superscript or in parentheses), assigned in order of first appearance.

Reading speed declines with age in monolingual adults (1).

Or with superscript (more common in journals):

Reading speed declines with age in monolingual adults¹.

After the first citation, the same number is used for any subsequent reference to that source:

Smith and colleagues showed that reading speed declines with age (1). They later replicated this finding in a multicenter study (2). The cognitive reserve effect, however, partially compensates this decline (1,3).

Reference list: numbered, in order of first appearance

The reference list is numbered in the order sources first appear in the text, NOT alphabetical (unlike APA, MLA, Chicago).

1. Smith J, Jones A. Reading speed and aging in monolingual adults. 
   J Cogn Aging. 2023;45(3):234-251.
2. Brown C, Davis M, Smith J. A multicenter replication of cognitive 
   decline in monolingual aging. Lancet Neurol. 2024;23(7):589-602.
3. Garcia M. Cognitive reserve and bilingualism. Nat Neurosci. 
   2022;25(4):412-420.

Author names: surname first, initials after (no commas, no periods)

Smith JP, Jones AB, Brown CD.

Note: no comma between surname and initials, no periods between initials. This is distinctive to Vancouver. Up to 6 authors are listed; for 7+, list the first 6 then "et al."

For 6 authors: Smith JP, Jones AB, Brown CD, Davis ME, Wilson F, Taylor GH.
For 7+ authors: Smith JP, Jones AB, Brown CD, Davis ME, Wilson F, Taylor GH, et al.

Journal abbreviations

Journal titles are abbreviated according to the NLM Title Abbreviation list (https://www.ncbi.nlm.nih.gov/nlmcatalog/journals). This is unique to Vancouver: no other major style requires journal abbreviations.

Examples:

• The Lancet → Lancet
• New England Journal of Medicine → N Engl J Med
• British Medical Journal → BMJ (this one is already abbreviated)
• Journal of the American Medical Association → JAMA
• Sleep Research Journal → Sleep Res J

PubMed automatically displays journal titles in NLM abbreviated form, useful when copying references.

No italics, sentence case for article titles

Article titles are in sentence case (only first word and proper nouns capitalized) and NOT italicized.

Journal titles are in title case (often) but NOT italicized either. This contrasts with APA, MLA and Chicago, which all italicize journal titles.

DOI mandatory when available

Vancouver follows the modern convention: DOI is mandatory when available, formatted as a hyperlink.

doi:10.NNNN/example

Reference List: Examples by Source Type

Journal article (standard, single author)

Smith J. Reading speed and aging in monolingual adults. J Cogn Aging. 
2023;45(3):234-251. doi:10.NNNN/example

Format: author(s). Article title. Journal abbreviated;year;volume(issue):pages. DOI.

Journal article (multiple authors)

Smith J, Jones A, Brown C. A multicenter trial of cognitive interventions 
in aging. Lancet. 2024;403(10421):589-602. doi:10.NNNN/example

Journal article (no DOI, online only)

Smith J. Memory consolidation during sleep. Sleep Res J. 2022;12(2):45-60.

Journal article without page numbers (epub ahead of print)

Smith J. Reading speed and aging. J Cogn Aging. 2024; Epub ahead of print. 
doi:10.NNNN/example

Book (single author)

Sherwood L. Human physiology. 4th ed. Brussels: De Boeck; 2019.

Format: author. Title. Edition. Place: Publisher; Year.

Book chapter (edited volume)

Dupuis M. Chronic pain assessment. In: Rey R, editor. Treatise on pain. 
3rd ed. Paris: Maloine; 2021. p. 234-256.

Government report

World Health Organization. Mental health and well-being. Geneva: WHO; 
2024. Report No.: WHO-MH-2024-01.

Webpage

World Health Organization. COVID-19 dashboard [Internet]. WHO; 2024 
[cited 2026 May 19]. Available from: https://covid19.who.int/

The "[Internet]" marker indicates an online source. The access date is in brackets.

Conference paper

Smith J. Working memory in older adults. In: Cognitive Neuroscience 
Society Annual Meeting; 2024 Mar 12-15; Toronto, Canada. p. 234.

Thesis or dissertation

Garcia M. Cognitive reserve and bilingualism in aging [doctoral 
dissertation]. Berkeley: University of California; 2022.

Database article (PubMed indexed)

PubMed citations follow Vancouver format. Copy from PubMed using the "Format as Citation" feature for accuracy:

Smith J, Jones A. Multicenter trial of cognitive interventions in aging. 
Lancet Neurol. 2024 Jul;23(7):589-602. PMID: 38912345. 
doi:10.NNNN/example

PMID (PubMed identifier) is sometimes added; not always required but useful.

Newspaper article

Goldstein D. Reading scores recover post-pandemic. The New York Times. 
2024 Apr 22; Sect. A:1.

AI-generated content (emerging guidance, ICMJE 2023-2024)

The ICMJE has issued guidance treating AI-generated content as a software tool to be cited in the methodology, not as an authoring source (authorship is reserved for accountable humans). For citation in the reference list:

OpenAI. ChatGPT (Mar 14, 2024 version) [Internet]. San Francisco: OpenAI; 
2024 [cited 2026 May 19]. Available from: https://www.example.com

The ICMJE explicitly states that AI cannot be listed as an author. Document AI use in the methods section per your journal's requirements (most major journals now require explicit AI disclosure).

Special Conventions for Medical Writing

Vancouver has several conventions specific to biomedical writing.

Personal communications

Personal communications (emails, letters, interviews) are cited in the text only, NOT in the reference list:

Personal communication with Dr. Smith (2024-04-15)

In a parenthetical:

(J. Smith, personal communication, 2024 Apr 15)

Unpublished material

Unpublished material can be cited but flagged:

Smith J. Reading speed in aging populations. Unpublished work; 2024.

Studies in progress

Smith J. Effects of cognitive training on aging populations. 
ClinicalTrials.gov NCT12345678. Estimated completion 2025.

Multiple citations

Several studies have shown this effect (1-3,5,7,9-12).

Hyphens for ranges, commas to separate.

Manuscript Formatting (When Submitting to a Medical Journal)

For thesis writing, Vancouver doesn't prescribe page layout. For journal submission, follow the specific journal's instructions (which may add to Vancouver).

Common conventions

• Title page: title, authors, affiliations, corresponding author, word count, conflict of interest, funding statement
• Abstract: structured (Background, Methods, Results, Conclusion) often required, 200-300 words
• Body: IMRaD structure (Introduction, Methods, Results, Discussion)
• References: numbered in order of first citation in the text
• Figures and tables: numbered separately, captioned, mentioned in text
• Word limit: typically 3500-5000 words for original research articles

Author contributions

Many journals require an author contributions statement. ICMJE has defined four criteria for authorship; contributors who don't meet all four should be acknowledged but not listed as authors.

Conflict of interest disclosure

Required by ICMJE: financial conflicts (funding, consulting, advisory roles), non-financial conflicts (institutional, personal). Use the ICMJE Form for Disclosure of Potential Conflicts of Interest.

Key Differences vs Other Citation Styles

Common Mistakes That Hurt Acceptance

Five mistakes that supervisors and journal editors flag most often.

Including periods between initials: Vancouver uses "Smith JP" not "Smith J. P." Periods are not used between initials.

Not abbreviating journal titles: Vancouver is unique in requiring NLM abbreviation. Use PubMed or the NLM Title Abbreviation list to verify.

Alphabetical reference list: Vancouver is NUMBERED in order of first citation, not alphabetical. This is the most common error from APA/MLA users.

Listing all authors for 7+ author papers: Vancouver uses first 6 + "et al." for 7 or more authors. Listing all is incorrect.

Italicizing journal titles: Vancouver does NOT italicize journal titles (unlike APA). Some students apply APA conventions habitually.

Reference Managers and Vancouver

Most reference managers support Vancouver:

• Zotero (free, open source): "Vancouver" style built-in; "Vancouver (superscript)" variant available
• Mendeley (free, by Elsevier): excellent Vancouver support
• EndNote (paid, by Clarivate): comprehensive Vancouver styles for multiple journals
• PubMed has a built-in citation export function in Vancouver format
• Folio Student: applies Vancouver layout automatically for biomedical thesis projects

Verify your manager's Vancouver style is current (ICMJE 2024). Older installations may be ICMJE 2019.

Pre-Submission Checklist (Vancouver Style)

• All in-text citations are numerical, in order of first appearance
• Same number reused for subsequent references to the same source
• Reference list numbered in order of first citation (not alphabetical)
• Author names: surname + initials without commas or periods (Smith JP)
• Up to 6 authors listed; 7+ uses first 6 + et al.
• Journal titles abbreviated per NLM
• Article titles in sentence case, not italicized
• Journal titles not italicized
• DOI included as hyperlink when available
• PMID included for PubMed-indexed sources (optional but useful)
• Conflict of interest disclosure if submitting to a journal
• Author contributions statement if required
• AI use disclosed per journal policy
• Final proofread for ICMJE 2024 compliance

For full details on related citation standards, see our APA 7 complete guide (US medicine often uses AMA 11, an APA-adjacent variant) and academic style guides reference.

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FAQ

Is Vancouver style still the current standard in 2026?
Yes. Vancouver is the international standard for medical publication. The ICMJE Recommendations are updated annually (current version: ICMJE 2024). Major medical journals (Lancet, NEJM, BMJ, JAMA) and PubMed all use Vancouver. The standard is widely adopted globally and is unlikely to change.

What's the difference between Vancouver and AMA?
Vancouver is the international standard for medical writing, while AMA (American Medical Association Manual of Style, 11th edition) is the US variant. They share the same numerical citation system but differ in some details (capitalization, journal abbreviation conventions). AMA is closer to Vancouver than to APA or MLA. Both are acceptable for medicine; choose based on your discipline and target journal.

Do I need to abbreviate journal titles?
Yes. Vancouver requires journal titles in their NLM (PubMed) abbreviated form. Use the NLM Title Abbreviation list or PubMed's "Format as Citation" feature to verify. This is unique to Vancouver; other styles use full journal titles.

Should I use superscript or parentheses for in-text numbers?
Both are acceptable. Superscript (1, 2, 3) is more common in journal articles. Parentheses (1), (2), (3) are common in theses and some textbooks. Choose one and use it consistently. Your journal's specific instructions may specify.

How many authors do I list before "et al."?
Six. List the first six authors in full, then "et al." for the seventh and beyond. This is a hard rule of Vancouver. Some journals allow fewer (3 + et al.) so check the specific journal's instructions.

Do I cite personal communications in the reference list?
No. Personal communications (emails, interviews, private conversations) are cited in the text only, never in the reference list. Format in the text: (J. Smith, personal communication, 2024 Apr 15).

How do I cite ChatGPT or other AI tools in Vancouver?
ICMJE 2023-2024 guidance treats AI as a software tool, not an authoring source. AI cannot be listed as an author. For citation:

OpenAI. ChatGPT (Mar 14, 2024 version) [Internet]. San Francisco: OpenAI; 2024. Available from: https://www.example.com

Document AI use in the methods section per your journal's policy. Most major medical journals now require explicit AI disclosure.

What is the difference between Vancouver and APA 7 for medical writing?
Vancouver is numerical (in-text 1, 2, 3) and numbered in order of citation in the reference list. APA 7 is author-date (Smith, 2023) and alphabetical. Vancouver is preferred for clinical and biomedical research worldwide. APA 7 is preferred for nursing research and some US-based medical fields. Your discipline and target journal will determine which to use.

Are journal titles italicized in Vancouver?
No. Vancouver does NOT italicize journal titles. This contrasts with APA, MLA and Chicago. Use plain (roman) text for journal titles, with the NLM abbreviation.

How do I cite a PubMed-indexed article in Vancouver?
Use PubMed's "Format as Citation" feature to copy the Vancouver-format citation. Include the PMID and DOI:

Smith J, Jones A. Multicenter trial. Lancet Neurol. 2024 Jul;23(7):589-602. PMID: 38912345. doi:10.NNNN/example

Should I cite preprints (e.g., bioRxiv, medRxiv)?
Vancouver allows preprint citations, but mark them as preprints:

Smith J. Reading speed and aging. medRxiv. 2024:2024.04.15.589123. [Preprint]. doi:10.NNNN/example

Check your journal's policy: some accept preprint citations, others require peer-reviewed publication only.

What if I'm citing a study in progress (not yet published)?
Cite as ongoing research with ClinicalTrials.gov or other registry reference:

Smith J. Effects of cognitive training. ClinicalTrials.gov NCT12345678. Estimated completion 2025.

This shows the research is ongoing and registered, increasing transparency.