Chicago 18th Edition: What Changed for Citations?

Chicago 18th edition changes at a glance

Citation issue	Chicago 18th edition
Authors in notes	List up to 2; for 3+, first author + et al.
Authors in Author-Date text citations	List up to 2; for 3+, first author + et al.
Authors in bibliography/reference list	List up to 6; for 7+, first 3 + et al.
Modern book publication place	No longer normally required
Edited-book chapter page range	No longer required in bibliography/reference list
Journal month or season	Can usually be omitted
Repeated authors in end lists	Repeat the author name rather than using a 3-em dash
Shortened notes	Author-title is regular short form; author-only/title-only also clarified
Footnote vs endnote omission	Nearby footnotes may omit information already clear in text more readily than endnotes
Eastern-order names	Not normally inverted
Shortened URLs	Expanded guidance
Archived web sources	New guidance for Wayback Machine and similar archives
Ahead-of-print/preprints	Updated and expanded guidance
AI-generated content	New citation guidance
Databases/datasets	Expanded guidance

The sections below explain which of these changes matter most for students, researchers, and citation-generator users.

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Is Chicago 18th edition the current edition?

Yes.

The 18th edition of The Chicago Manual of Style was published by the University of Chicago Press in 2024 and remains the current numbered edition in 2026.

Chicago’s editorial policy states that the substantive style rules of an edition remain consistent throughout that edition’s life. Typographical corrections and minor clarifications can be made online and incorporated into later printings, but the Manual is not silently converted into a new numbered edition.

That means:

Correct: Chicago 18th edition Correct when true: reviewed or updated for 2026 Incorrect: Chicago 2026 edition Incorrect: Chicago 2026 style

If your instructor specifically requires Chicago 17th edition, follow that assignment requirement rather than automatically converting the paper to Chicago 18.

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What are the biggest citation changes from Chicago 17 to Chicago 18?

For most users, six changes have the greatest practical effect:

1. author thresholds changed;
2. modern books normally omit place of publication;
3. book-chapter page ranges are no longer required in end-list entries;
4. journal month or season can usually be omitted;
5. repeated authors are written again instead of replaced by a 3-em dash;
6. shortened citations were clarified.

These changes can alter citations even when the underlying source metadata has not changed.

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1. Chicago 18 changed how many authors are listed

This is one of the most important changes because it affects both Chicago systems.

Notes and Author-Date text citations

Chicago 18 lists:

• 1 author: list the author;
• 2 authors: list both;
• 3 or more authors: first author + et al.

Bibliography and reference-list entries

Chicago 18 lists:

• 1–6 authors: list all authors;
• 7 or more authors: first 3 authors + et al.

Quick table

Number of authors	Note	Author-Date in-text	Bibliography / reference list
1	1 author	1 author	1 author
2	Both	Both	Both
3–6	First + et al.	First + et al.	List all
7+	First + et al.	First + et al.	First 3 + et al.

This is especially important for journal articles, which often have long author lists.

For source-specific examples, see Chicago Journal Article Citation and Chicago Book Citation.

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2. Chicago 18 normally removes the place of publication for modern books

Older Chicago citations commonly included a city before the publisher.

A Chicago 17-style book entry might look like:

Author. Book Title. New York: Publisher, Year.

Chicago 18 no longer normally requires the place of publication for modern books.

The current basic structure is:

Author. Book Title. Publisher, Year.

Example structure

Older pattern

Bennett, Maya. Cities at Dusk. New York: Northfield Press, 2025.

Chicago 18 pattern

Bennett, Maya. Cities at Dusk. Northfield Press, 2025.

The example is fictional and is included only to show the structural change.

Does this apply to every historical book?

No.

Older works, especially books published before 1900, can require different treatment. Chicago’s current examples show that place may sometimes be useful for historical books.

Do not remove historically meaningful publication information blindly.

For the current whole-book rules, see Chicago Book Citation.

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3. Chicago 18 removes the full page range for a cited book chapter

This is another major difference from older Chicago examples.

Under Chicago 17, a bibliography or reference-list entry for a chapter in an edited book normally included the chapter’s complete page range.

Chicago 18 no longer requires that page range in the standard end-list entry.

Chicago 18 concept

Bibliography

Chapter Author. “Chapter Title.” In Book Title, edited by Editor. Publisher, Year.

The chapter’s complete range is omitted.

But what about the page I actually cited?

The specific page or pages you used still matter in the note or Author-Date citation.

For example:

Shortened note

Ruiz, “Reading the Industrial City,” 68.

Author-Date

(Ruiz 2025, 68)

The key distinction is:

• full chapter page range → no longer required in the bibliography/reference list;
• specific cited page → still used when relevant.

This does not apply to most journal articles. Journal bibliography/reference-list entries still normally include the article’s full page range.

See Chicago Book Chapter Citation for the complete rule.

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4. Journal month or season can usually be omitted

Chicago 18 says a month or season can now usually be omitted from journal-article citations.

Older examples may include information such as:

• Spring 2023;
• March 2024;
• Winter 2022.

When the volume, issue, and year adequately identify the journal article, the month or season is generally unnecessary.

Chicago 18 structure

Journal Title 51, no. 2 (2025): 201–24.

rather than automatically including an additional month or season.

This change reduces unnecessary publication detail while keeping the article identifiable.

For journal volume, issue, DOI, page-range, and article-ID examples, see Chicago Journal Article Citation.

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5. Chicago 18 prefers repeating author names instead of a 3-em dash

Older Chicago bibliographies commonly replaced a repeated author’s name with a long 3-em dash in successive entries.

Chicago 18 now prefers repeating the author name.

Current approach

Bennett, Maya. Cities at Dusk. …

Bennett, Maya. Mapping the Quiet City. …

Older approach

Bennett, Maya. Cities at Dusk. …

———. Mapping the Quiet City. …

If you are following Chicago 18, do not automatically reproduce the 3-em-dash convention from an older handbook or citation website.

See Chicago Bibliography for ordering, hanging indents, repeated authors, and end-list mechanics.

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6. Chicago 18 clarifies shortened citations

Chicago continues to prefer shortened citations over repeated full notes.

The 18th edition clarifies three shortened forms:

1. author + title
2. author only
3. title only

Chicago identifies author + title as its regular short form.

Example

Full note

Maya Bennett, Cities at Dusk (Northfield Press, 2025), 73.

Regular shortened note

Bennett, Cities at Dusk, 81.

Possible author-only short form when unambiguous

Bennett, 81.

Possible title-only short form when unambiguous

Cities at Dusk, 81.

The source above is fictional.

The shorter forms should be used only when readers can still identify the source without confusion.

For detailed repeated-note guidance, see Chicago Footnotes.

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Does Chicago 18 still allow “ibid.”?

Yes, but Chicago prefers shortened citations.

A shortened note such as:

Bennett, Cities at Dusk, 81.

identifies the source directly and remains understandable if notes are inserted or reordered.

Ibid. refers to the source in the immediately preceding note and can become less clear during revision.

If your instructor or publisher specifically requires ibid., follow that instruction.

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7. Footnotes can omit nearby information more readily than endnotes

Chicago 18 clarifies that citation information already stated in the main text can sometimes be omitted from a footnote, because the footnote appears close to the sentence.

That same omission is usually less suitable for an endnote, where the reader encounters the citation farther away from the original wording.

This does not mean that every footnote should be aggressively shortened.

Use enough information to keep the note clear.

For detailed note placement and footnote/endnote differences, see Chicago Footnotes.

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8. Eastern-order personal names are not normally inverted

Chicago 18 clarifies treatment of names that naturally follow Eastern order, with the family name first.

Such names are not normally inverted in a bibliography or reference list merely to imitate Western-order naming conventions.

The official Chicago examples use author names such as:

Liu Xinwu

without turning the bibliography entry into:

Xinwu, Liu

unless the author’s own naming practice calls for a different presentation.

This change supports more accurate treatment of names across languages and cultures.

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9. Alphabetization of repeated-author works was clarified

When several works by the same author are ordered by title, Chicago 18 clarifies that an initial English:

• A
• An
• The

is ignored for alphabetization.

For example:

The City at Night

would be alphabetized under C, not T.

Chicago specifically notes that this English-article rule does not automatically apply to foreign-language articles such as Le or Un.

For detailed bibliography ordering, see Chicago Bibliography.

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10. Chicago 18 adds clearer guidance on mentioning a source vs formally citing it

Not every source mention needs a full formal citation.

Chicago 18 expands guidance on the difference between:

• mentioning a source, and
• formally citing a source.

This distinction is particularly useful for websites and informal online material.

For example, an ordinary website home page may sometimes be identified clearly in the sentence without adding a full bibliography entry.

A formal citation becomes more useful when:

• the source supports a substantive claim;
• readers need to locate it;
• the assignment requires documentation;
• the source belongs in the bibliography/reference list.

See Chicago Website Citation for practical web examples.

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11. Chicago 18 expands guidance on shortened URLs

The 18th edition gives more guidance on using shortened or cleaner URLs.

The practical goal is to cite a stable, useful location without unnecessary clutter.

Prefer:

• a canonical page URL;
• a DOI-based URL for a scholarly article;
• an official stable link;
• an archive URL when citing a preserved version.

Avoid unnecessary tracking parameters when the same page can be reached without them.

For website URL examples, see Chicago Website Citation.

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12. Chicago 18 adds explicit guidance for archived web sources

Chicago 18 includes new guidance for citing sources archived with services such as the Internet Archive’s Wayback Machine.

An archived citation can be useful when:

• a webpage changed;
• a webpage disappeared;
• a historical version matters;
• readers need to see the version you actually consulted.

This is especially useful for:

• policy pages;
• home pages;
• frequently changing organizational content;
• web-only evidence.

See Chicago Website Citation for access dates, n.d., last-modified dates, and archived pages.

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13. Ahead-of-print articles, forthcoming articles, and preprints received expanded guidance

Chicago 18 expands its treatment of journal material that has not yet reached a conventional final issue.

This includes:

• ahead-of-print articles;
• forthcoming articles;
• preprints.

These publication states are not interchangeable.

Ahead of print

The article has been published online but may not yet have final issue information.

Forthcoming

The work has been accepted for publication but is not yet formally published.

Preprint

The manuscript has been made publicly available before formal journal publication.

Cite the publication state you actually used.

Do not invent:

• issue numbers;
• final page ranges;
• publication years;
• journal details

that have not been assigned.

See Chicago Journal Article Citation for the journal-specific workflow.

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14. Chicago 18 adds guidance for AI-generated content

The 18th edition includes new guidance on citing AI-generated content.

This is broader than the launch scope of ChicagoReferenceGenerator.com, so this site does not create a separate AI citation page at launch.

The important architectural rule is:

• AI citation guidance belongs under Chicago 18/current-source guidance until keyword demand and product support justify a dedicated page.

Do not treat an AI-generated response as though it were a journal article, ordinary webpage, or book.

A dedicated /chicago-ai-citation/ page may be considered in a future phase if search demand and generator support justify it.

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15. Databases and datasets received expanded guidance

Chicago 18 expands guidance for citing databases and datasets.

These sources can require metadata beyond a conventional webpage, including:

• dataset creator;
• dataset title;
• repository;
• version;
• publication or release date;
• DOI or persistent identifier.

A dataset viewed through a browser is not automatically an ordinary webpage.

This site does not create a separate dataset citation page at launch, but the source type can be considered in Phase 2.

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16. Chicago 18 adds new guidance for Wayback Machine, AI, Indigenous sources, and more

The 18th edition also expands source-citation coverage for areas including:

• archived web sources;
• AI-generated content;
• Indigenous sources;
• illustrators;
• databases and datasets;
• ahead-of-print/forthcoming journal articles;
• preprints.

Not all of these changes affect every student paper, but they show why Chicago 18 should be treated as a meaningful edition update rather than a cosmetic renumbering.

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Chicago 17 vs Chicago 18: book example

A modern book shows one of the clearest visible differences.

Older-style structure

Bennett, Maya. Cities at Dusk. New York: Northfield Press, 2025.

Chicago 18 structure

Bennett, Maya. Cities at Dusk. Northfield Press, 2025.

The example is fictional.

The publication city is no longer normally required.

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Chicago 17 vs Chicago 18: chapter example

Older-style structure

Ruiz, Elena. “Reading the Industrial City.” In Urban Memory and Place, edited by Maya Bennett and Daniel Cho, 45–68. New York: Northfield Press, 2025.

Chicago 18 structure

Ruiz, Elena. “Reading the Industrial City.” In Urban Memory and Place, edited by Maya Bennett and Daniel Cho. Northfield Press, 2025.

The example is fictional.

Chicago 18 removes:

• the full chapter page range;
• the modern publication city.

The specific page being cited still belongs in the note or Author-Date citation.

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Chicago 17 vs Chicago 18: author threshold example

Imagine a journal article with three authors:

Maya Bennett, Daniel Cho, and Elena Ruiz.

Chicago 18 note

Bennett et al., “Article Title,” 45.

Chicago 18 Author-Date

(Bennett et al. 2026, 45)

Chicago 18 bibliography/reference list

All three authors are listed.

Do not use one author-shortening threshold for every citation output.

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Chicago 17 vs Chicago 18: repeated authors

Older bibliography convention

Bennett, Maya. Cities at Dusk. …

———. Mapping the Quiet City. …

Chicago 18 preference

Bennett, Maya. Cities at Dusk. …

Bennett, Maya. Mapping the Quiet City. …

The repeated-name form is now preferred.

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Did Chicago 18 change both Notes & Bibliography and Author-Date?

Yes.

The 18th-edition changes affect both systems, though some changes appear differently depending on the output.

Notes & Bibliography

Important changes include:

• new note author thresholds;
• clarified shortened notes;
• publication-place omission for books;
• chapter page-range omission in bibliographies;
• repeated-author treatment;
• footnote/endnote clarification.

See Chicago Notes & Bibliography and Chicago Footnotes.

Author-Date

Important changes include:

• new text-citation author thresholds;
• new reference-list author thresholds;
• book publication-place omission;
• chapter page-range omission;
• repeated-author treatment;
• journal-date simplification.

See Chicago Author-Date.

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Does Chicago 18 change bibliography formatting?

Yes, in several important ways.

The most visible changes include:

• list up to six authors;
• for more than six, use first three + et al.;
• repeat an author’s name instead of using a 3-em dash;
• omit the place of publication for modern books;
• omit the full page range for cited chapters in edited books;
• apply clarified name-order and alphabetization rules.

For the full end-list workflow, see Chicago Bibliography.

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Does Chicago 18 change footnotes?

Yes.

Important footnote-related changes and clarifications include:

• notes list up to two authors;
• three or more authors use first author + et al.;
• shortened citation options are clarified;
• shortened citations remain preferred over ibid.;
• information already stated in the main text may sometimes be omitted from a nearby footnote;
• book publication cities normally disappear from modern book notes.

For detailed examples, see Chicago Footnotes.

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Are Chicago 17 citations automatically wrong?

No.

A Chicago 17 citation can be correct for an assignment or publication that explicitly requires the 17th edition.

It may also contain optional information that Chicago 18 no longer requires without being impossible to understand.

The problem is claiming that a citation is Chicago 18 while applying old rules by default.

If your instructor says:

Chicago 17th edition

follow Chicago 17.

If the instructions simply say:

Chicago style

check whether the institution expects the current 18th edition.

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Can I leave old Chicago 17 citations unchanged in an existing paper?

That depends on the purpose of the document.

For an old published paper, there is usually no reason to rewrite historical citations merely because a new style edition exists.

For a manuscript being newly submitted under Chicago 18, review the citations against the current rules.

Pay particular attention to:

• long author lists;
• publication cities;
• chapter page ranges;
• repeated-author dashes;
• journal month/season information;
• shortened notes.

A citation manager can help with formatting changes, but the source metadata still needs to be correct.

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What should I update when converting a Chicago 17 bibliography to Chicago 18?

Use this checklist:

Books

• remove publication city when it is not needed;
• keep publisher and year;
• verify editions and contributor roles.

Book chapters

• remove full chapter page ranges from standard bibliography/reference-list entries;
• keep specific cited pages in notes/text citations.

Author lists

• apply the Chicago 18 thresholds;
• do not keep old truncation rules.

Repeated authors

• replace 3-em dashes with repeated author names.

Journal articles

• remove month/season where it is not needed;
• keep full article page range or article ID in the end-list entry;
• keep specific cited pages in notes/text citations.

Names

• review Eastern-order names before inverting them.

URLs

• use stable, clean links and DOI URLs where appropriate.

Then compare your source-specific citations against:

• Chicago Book Citation
• Chicago Journal Article Citation
• Chicago Website Citation
• Chicago Book Chapter Citation

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How does ChicagoReferenceGenerator.com use Chicago 18?

The generator is designed around maintained Chicago 18th-edition CSL styles and a CSL citation processor rather than manually assembling every citation with hard-coded punctuation templates.

The workflow is:

Source lookup or manual entry ↓ Normalized source record ↓ Metadata review ↓ Chicago system selection ↓ Chicago 18 CSL formatting ↓ Citation output

The generator supports both:

Notes & Bibliography

• Full Note
• Shortened Note
• Bibliography Entry

Author-Date

• In-Text Citation
• Reference List Entry

A cited page or other locator is kept separate from permanent source metadata.

For the technical implementation, external metadata sources, duplicate handling, and current limitations, see How the Chicago Citation Generator Works.

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Important current generator limitation for edited-book chapters

Chicago 18 chapter citations require contributor roles such as:

• chapter author;
• editor;
• sometimes translator.

The current plugin version includes a Book chapter source type, but it does not yet expose dedicated editor or translator fields in its metadata editor or pass those roles through the complete citation-data pipeline.

That means edited-book chapter citations require manual verification until contributor support is added.

See Chicago Book Chapter Citation for the exact citation requirements.

This limitation does not change the Chicago 18 rule itself; it is a current product implementation issue.

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Why do some citation websites still show Chicago 17?

Citation websites, university handouts, reference managers, and templates do not all update at the same time.

A page may:

• explicitly say Chicago 17;
• use a Chicago 18 heading but retain older examples;
• update some rules but not others;
• rely on an older citation-style file;
• mix Chicago with Turabian guidance.

Before copying an example, check:

1. which edition it actually follows;
2. whether the source type matches yours;
3. whether it is Notes & Bibliography or Author-Date;
4. whether the example reflects current author thresholds;
5. whether old book/chapter conventions remain.

For citation rules on this site, official Chicago 18 material is the primary authority.

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Is Chicago 18 the same as Turabian?

No.

Chicago and Turabian are closely related, but they are not the same publication.

Turabian is a separate student-oriented manual with its own edition and student-paper guidance.

ChicagoReferenceGenerator.com does not automatically label Chicago 18 output as Turabian and does not target “Turabian citation generator” at launch.

If future keyword research supports it, a separate informational Chicago-vs-Turabian comparison may be considered.

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Has Chicago 18 changed since 2024?

The numbered edition has not changed.

Chicago’s editorial policy says its 18th-edition style guidance remains substantively consistent throughout the life of the edition.

The official corrections page can publish:

• typographical corrections;
• cross-reference corrections;
• minor clarifications.

As of the current 2026 review, the corrections page includes some citation-related clarifications, such as clarification of when a journal article’s full page range appears in a full note that cites the article as a whole rather than specific pages.

This is why important citation content should still be checked against the current official online material even when the numbered edition has not changed.

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Frequently asked questions

What is Chicago 18th edition?

Chicago 18th edition is the current edition of The Chicago Manual of Style, published in 2024. It includes updated guidance on writing, editing, publishing, and source citations.

Is there a Chicago 2026 edition?

No. The current numbered edition in 2026 is Chicago 18th edition. Content can be reviewed or updated in 2026, but it should not be called the “Chicago 2026 edition.”

What is the biggest Chicago 18 citation change?

There is no single change that affects every source, but the most important practical changes include new author thresholds, removal of publication place for modern books, removal of chapter page ranges from end-list entries, and the preference for repeating author names instead of using 3-em dashes.

How many authors do I list in Chicago 18?

In notes and Author-Date text citations, list up to two authors; for three or more, use the first author + et al. In bibliography/reference-list entries, list up to six; for more than six, list the first three + et al.

Does Chicago 18 require a city for book citations?

No. A place of publication is no longer normally required for modern books.

Does Chicago 18 require a book chapter page range?

No. The full chapter page range is no longer required in a standard bibliography or reference-list entry. Specific cited pages still belong in notes or Author-Date citations.

Do journal citations still include page ranges?

Yes. Most journal bibliography/reference-list entries still include the full article page range when the article has traditional pages. An article ID can replace the page range for journals that use e-locations.

Do I include journal month or season?

Usually not. Chicago 18 says a month or season can now usually be omitted.

Does Chicago 18 still use the 3-em dash for repeated authors?

Chicago now prefers repeating the author’s name in bibliography and reference-list entries.

Does Chicago 18 still allow ibid.?

Yes, but Chicago prefers shortened citations. Author-title is the regular short form.

Did Chicago 18 change website citations?

Chicago 18 adds or expands guidance on mentioning versus formally citing sources, shortened URLs, archived webpages, and other online-source cases.

Does Chicago 18 cover AI citations?

Yes. The 18th edition adds guidance on citing AI-generated content.

Should I update an old paper from Chicago 17 to Chicago 18?

Only if the document is being revised or submitted under current Chicago 18 requirements. A historically completed or published paper does not automatically need retroactive citation changes.

Can I use the generator for Chicago 18?

Yes. The generator is designed around Chicago 18 CSL styles for Notes & Bibliography and Author-Date. Always review the source metadata and finished citation before submission.

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Official Chicago sources

This guide was researched against current official Chicago 18th-edition material:

• What’s New in the 18th Edition
• Chicago-Style Citation Quick Guide
• Notes and Bibliography: Sample Citations
• Author-Date: Sample Citations
• Editorial Policy
• Corrections to the 18th Edition

ChicagoReferenceGenerator.com is an independent citation resource and is not affiliated with or endorsed by The University of Chicago or The University of Chicago Press. The Chicago Manual of Style is a registered trademark of The University of Chicago.

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Continue with the guide you need

• Generate a Chicago Citation
• Chicago Style Guide
• Chicago Notes & Bibliography
• Chicago Author-Date
• Chicago Footnotes
• Chicago Bibliography
• Chicago Citation Examples
• Chicago Book Citation
• Chicago Journal Article Citation
• Chicago Website Citation
• Chicago Book Chapter Citation