JAMA Formatting Requirements: Complete Author Guide

JAMA publishes several article types, each with distinct word limits. Going over these limits is one of the fastest ways to get an administrative rejection before your paper even reaches an editor.

Word counts exclude the abstract, references, figure legends, and table content. Don't try to game this by shifting body text into figure legends. Editors notice.

JAMA requires structured abstracts for Original Investigations and Reviews. The abstract can't exceed 350 words and must use these specific headings in this exact order:

For Original Investigations:

• Importance (not "Background" or "Introduction")
• Objective
• Design, Setting, and Participants
• Interventions (if applicable)
• Main Outcomes and Measures
• Results
• Conclusions and Relevance (not just "Conclusions")

This is where many authors slip up. JAMA doesn't use the standard IMRAD abstract structure that most journals accept. If you submit with "Background" instead of "Importance" or "Conclusions" instead of "Conclusions and Relevance," you'll get sent back for reformatting.

The Importance section should be 1-2 sentences establishing why this research matters clinically. Don't waste space on broad epidemiological context that reviewers already know. The Conclusions and Relevance section must directly address the clinical implications, not just restate results.

JAMA requires a title page as the first page of your manuscript. It must include:

• Full manuscript title (no abbreviations allowed in the title)
• All author names with highest academic degrees
• Institutional affiliations for each author
• Corresponding author name, address, phone, and email
• Word count of body text and abstract separately
• Number of figures and tables
• Date of manuscript completion

One quirk that catches people: JAMA wants you to list the highest academic degrees after each author name using standard abbreviations (MD, PhD, MPH). Don't include honorary degrees. If an author holds both an MD and a PhD, list both.

JAMA permits a maximum of 5 display items (figures and tables combined) in the main manuscript. Anything beyond that goes into the eSupplement.

Figure requirements:

• Minimum resolution: 300 DPI for photographs, 600 DPI for line art
• Accepted formats: TIFF, EPS, or high-resolution PDF
• Maximum width: 3.25 inches (single column) or 6.75 inches (double column)
• Font in figures: Arial or Helvetica, minimum 8-point
• Color figures are published at no extra cost
• Each figure must be uploaded as a separate file

Table requirements:

• Tables must be created in Word using the table function (not as images)
• Every column must have a header
• Use horizontal rules only at the top, bottom, and below column headers
• No vertical rules
• Abbreviations in tables must be defined in footnotes
• P values should be reported to 2 or 3 decimal places

Figures that combine multiple panels (A, B, C, etc.) count as one display item. This is your best strategy for staying under the 5-item limit. Group related results into composite figures whenever possible.

JAMA follows the AMA Manual of Style, 11th edition. This is non-negotiable, and it's different enough from Vancouver style that you can't just use "close enough" formatting.

Key AMA reference rules:

• Citations appear as superscript numbers in the text, placed after punctuation
• References are numbered consecutively in order of first citation
• List all authors when there are 6 or fewer; for 7 or more, list the first 3 followed by "et al"
• Journal names are abbreviated according to NLM standards
• Don't include issue numbers for journals with continuous pagination

Example journal article reference:

Smith AB, Jones CD, Williams EF. Association of sleep duration with mortality in older adults. JAMA. 2026;335(4):412-420. doi:10.1001/jama.2026.1234

Example book chapter reference:

Johnson KL. Clinical pharmacology. In: Roberts MN, ed. Handbook of Internal Medicine. 5th ed. Elsevier; 2025:142-168.

Most reference managers handle AMA style reasonably well, but always manually check for the author cutoff rule and issue number inclusion. These are the two most common errors in JAMA reference formatting.

JAMA uses the term "eSupplement" rather than "supplementary materials" or "supporting information." All eSupplement content is peer-reviewed and published online only.

Your eSupplement should be compiled into a single document with the following structure:

• eMethods: Additional methodological details
• eFigures: Numbered sequentially (eFigure 1, eFigure 2, etc.)
• eTables: Numbered sequentially (eTable 1, eTable 2, etc.)
• eReferences: References cited only in the eSupplement

Each element in the eSupplement must be cited in the main manuscript text. Don't dump extra data into the eSupplement without referencing it. The prefix "e" is required for all supplementary items. Write "eTable 3" in your manuscript, not "Supplementary Table 3."

There's no formal word limit on the eSupplement, but editors discourage excessive length. If your eSupplement is longer than your main manuscript, consider whether some of that material should be in the main text instead, or whether it's truly necessary.

JAMA has several formatting rules that differ from other major medical journals. Missing these is a common source of administrative returns.

1. The "Importance" heading in abstracts. Most medical journals use "Background" or "Introduction." JAMA uses "Importance." This isn't optional.

2. Statistical reporting requirements. JAMA requires specific statistical formatting: report exact P values to 2-3 decimal places (P = .03, not P < .05), include 95% confidence intervals for all primary outcomes, and use the capital-italic format (P, not p).

3. No abbreviations in the title. Unlike many journals that allow common abbreviations (RCT, BMI, CI), JAMA prohibits all abbreviations in the manuscript title. Spell everything out.

4. Conflict of interest and funding placement. JAMA requires conflict of interest disclosures and funding information at the end of the manuscript, before references. These aren't relegated to a separate form. They appear in the published article.

5. Key Points box. Original Investigations must include a "Key Points" box with three elements: Question (1 sentence), Findings (2 sentences max), and Meaning (1 sentence). This appears at the beginning of the published article and is one of the most-read sections.

6. Author contributions using CRediT taxonomy. JAMA requires authors to describe contributions using the CRediT (Contributor Roles Taxonomy) framework rather than free-text contribution statements.

The body of a JAMA Original Investigation follows this mandatory structure:

1. Introduction (keep it short, 2-3 paragraphs)
2. Methods (including study design, setting, participants, interventions, outcomes, statistical analysis)
3. Results (organized to match the Methods section)
4. Discussion (interpret findings, compare with existing literature, discuss limitations, state conclusions)

JAMA's Introduction section should be notably brief. Two to three paragraphs that identify the gap in knowledge and state the study objective. Don't provide an exhaustive literature review. Save the context for the Discussion.

The Methods section must include an ethics statement specifying IRB approval and informed consent procedures. For clinical trials, the registration number and registry name are required.

After working with hundreds of JAMA submissions, these are the errors we see most frequently:

• Using "Background" instead of "Importance" in the structured abstract
• Exceeding the 5-item limit for figures and tables
• Including abbreviations in the manuscript title
• Formatting P values incorrectly (lowercase p, or using < instead of exact values)
• Forgetting the Key Points box
• Numbering eSupplement items without the "e" prefix
• Submitting in LaTeX without a companion PDF
• Missing the word count on the title page
• Using Vancouver reference style instead of AMA style

Each of these will trigger an administrative return, adding days or weeks to your timeline before the manuscript even reaches peer review.

For detailed answers to common JAMA formatting questions, see the FAQ section above. The most common confusion points are around the eSupplement naming convention, the structured abstract headings, and the 5-item display limit.

If you're comparing JAMA with other top medical journals, see our BMJ formatting requirements guide for a side-by-side comparison. For broader submission strategy, check our guide on how to avoid desk rejection at JAMA.

For the full, official author guidelines, visit the JAMA Instructions for Authors page.