Referencing & Formatting

Chicago Citation Style: Notes & Author-Date

Updated September 8, 2026

Chicago Style Uses Two Citation Systems

Chicago style is unusual among major academic referencing systems because it supports two complete documentation systems: notes and bibliography, and author-date. The current Chicago Manual of Style is the 18th edition, published in 2024. Its official Chicago-Style Citation Quick Guide explains that students should use the system required by their instructor, publisher, department, or discipline rather than switching between the two inside one paper.

In notes and bibliography, a superscript number in the text points to a footnote or endnote, and cited sources are usually collected in a bibliography. In author-date, the source appears briefly in parentheses in the text, normally as author surname plus year, and a matching reference-list entry supplies the full details.

For the broader role of citations, source lists, and style selection, start with the complete guide to academic referencing and formatting. If you are deciding between Chicago and another system, use the comparison pillar rather than converting examples line by line.

The focused comparison is APA vs MLA vs Harvard vs Chicago: Citation Styles Compared, which explains why two author-date systems can still format the same source differently.

Chicago 18th Edition: What Students Need to Know

The 18th edition reorganized and updated source-citation guidance. The manual now presents both citation systems together more closely, with chapter 13 providing the source-citation overview and chapter 14 organizing examples by source type. Chicago also changed several details that students may see handled differently in older guides. The official What’s New in the 18th Edition is the best place to check edition-specific changes.

18th-edition point	Practical effect for students
Author lists	Bibliography/reference-list entries list up to six authors; for more than six, list the first three followed by “et al.”
Notes and author-date text citations	Up to two authors are listed; for more than two, the first author is followed by “et al.”
Book publication place	A place of publication is no longer required in ordinary book citations.
Book chapters	A chapter page range is no longer required in bibliography/reference-list entries; a note can cite the specific page used.
Repeated bibliography authors	Chicago now prefers repeating author names instead of replacing them with a 3-em dash.
Journal dates	A month or season can usually be omitted from journal-article citations.

Many web pages and citation generators still reproduce older Chicago 17 patterns. If an example conflicts with a current official Chicago 18 source, use the current rule unless your instructor explicitly requires an older edition.

Notes and Bibliography vs Author-Date at a Glance

Feature	Notes and Bibliography	Author-Date
Citation in the text	Superscript note number	Parenthetical author + year
Detail near the claim	Footnote/endnote can carry substantial source detail	Citation stays compact
Final list	Bibliography, usually alphabetical	Reference list, alphabetical
Dates	Often appear later in bibliography entries	Year appears immediately after author in reference list
Common disciplinary association	Humanities, history, literature, arts	Sciences and social sciences
Repeated citation	Shortened note after first full note	Repeat author-year citation
Unusual sources	Very flexible because notes can explain context	Works best when source fits author-date logic

How the Notes and Bibliography System Works

In notes and bibliography, the first citation of a source normally appears in a numbered footnote or endnote. The superscript note number follows the relevant sentence, clause, or quotation. The note itself gives enough publication information for the reader to identify the source. If the source is cited again, Chicago normally uses a shortened note rather than repeating the full citation.

A separate bibliography usually lists the cited sources alphabetically by author surname. A bibliography entry is not simply a footnote with different punctuation. Names are reordered, parentheses are removed, and some source details move or disappear. Treat notes and bibliography entries as related but distinct formats.

If the distinction between a short source marker and a full source record is still unclear, review what is an in-text citation and then return to Chicago’s note-based model.

Full Note, Shortened Note, and Bibliography Entry

The fictional examples below illustrate the structural differences. They are models for learning, not real sources.

Book — first full note (fictional)

1. Amina K. Njoroge, Learning Through Evidence (Northbridge Academic, 2025), 74.

Book — shortened note (fictional)

2. Njoroge, Learning Through Evidence, 91.

Book — bibliography entry (fictional)

Njoroge, Amina K. Learning Through Evidence. Northbridge Academic, 2025.

The first note uses the author’s normal name order and places publication details in parentheses. The shortened note uses surname, a shortened title, and the relevant locator. The bibliography inverts the first author’s name so the entry can be alphabetized.

Where the Superscript Number Goes

Chicago notes use a raised superscript number in the text, not a number placed in parentheses. Put the note number after the punctuation that closes the relevant sentence or clause, unless the instructor or a special context requires something different. Word processors can create footnotes automatically; do not type superscript numbers manually and then build notes by hand at the bottom of the page.

Text with a note callout

Revision improves when students connect feedback to a specific next action.¹

A properly inserted footnote keeps numbering synchronized if you add, remove, or move notes later.

Shortened Notes and Repeated Sources

Chicago 18 allows shortened citations in place of “ibid.” A normal shortened note uses the author surname, a concise version of the title, and a page or other locator when useful. In some contexts an author-only or title-only short form can work, but it must remain unambiguous.

Do not repeat the entire first note every time a source appears. Repeated full notes make the paper harder to read and increase the chance that two versions of the same source will drift apart during editing.

How the Author-Date System Works

Chicago author-date keeps citation information in the body of the paper. A typical citation gives the author surname and year, with a page or other locator after a comma when the reference is to a specific passage. Each citation matches a full entry in the reference list.

Parenthetical author-date citation (fictional)

Evidence is easier to evaluate when the source trail remains visible (Njoroge 2025, 74).

Narrative author-date citation (fictional)

Njoroge (2025, 74) argues that evidence should be connected to an explicit analytical purpose.

Author-date reference-list entry (fictional)

Njoroge, Amina K. 2025. Learning Through Evidence. Northbridge Academic.

The author-date system therefore resembles APA and many Harvard variants at a distance, but the punctuation, capitalization, ordering, and source-specific details follow Chicago rules. Do not convert an APA reference simply by deleting parentheses around the year.

Two Authors, Three or More Authors, and the 18th-Edition Rule

Chicago 18 simplified author treatment. In a note or author-date text citation, list up to two authors. For three or more authors, use the first author’s name followed by “et al.” In a bibliography or reference-list entry, list up to six authors; when there are more than six, list the first three followed by “et al.”

Author-date — two authors (fictional)

(Omondi and Reed 2025, 41)

Author-date — three or more authors (fictional)

(Chen et al. 2026, 118)

Because this rule changed from older Chicago guidance, verify that your citation manager is configured for the 18th edition.

How to Cite a Book in Chicago Style

For a standard book, record the author, title, publisher, and year. Chicago 18 no longer requires the place of publication in ordinary book citations. The exact punctuation and year placement depend on which documentation system you are using.

Form	Fictional model
Full note	1. Daniel O. Mensah, Designing Better Assignments (Cedar Press, 2024), 62.
Shortened note	2. Mensah, Designing Better Assignments, 79.
Bibliography	Mensah, Daniel O. Designing Better Assignments. Cedar Press, 2024.
Author-date citation	(Mensah 2024, 62)
Reference list	Mensah, Daniel O. 2024. Designing Better Assignments. Cedar Press.

For an edition other than the first, add the edition information after the title. For an e-book, online book, or database copy, follow the current source-specific rule for format, database name, DOI, or URL. The official quick guide gives current examples for print and electronic books.

How to Cite a Chapter in an Edited Book

When you use a chapter written by one author inside an edited collection, cite the chapter rather than treating the editor as the chapter author. Chicago 18 no longer requires the chapter’s full page range in a bibliography or reference-list entry, although a note can still identify the specific page you used.

Notes-bibliography chapter model (fictional)

1. Lena Park, “Peer Review as Revision,” in Writing in Practice, ed. Omar Bell and Nia Santos (Rivergate Press, 2025), 88.

Bibliography model (fictional)

Park, Lena. “Peer Review as Revision.” In Writing in Practice, edited by Omar Bell and Nia Santos. Rivergate Press, 2025.

If the entire edited collection is what you are citing, format the editors as the responsible creators of the whole book instead.

How to Cite a Journal Article

Journal articles normally include the author, article title, journal title, volume, issue number, year, and article page range or article identifier. In notes, cite the specific page used. In a bibliography, include the article’s full page range when the journal uses pages. For an online article, Chicago prefers a DOI-based URL when available; a database name can be used in appropriate cases.

Form	Fictional model
Full note	1. Imani Patel, “Feedback Timing and Student Revision,” Journal of Learning Practice 18, no. 2 (2025): 144, https://doi.org/10.0000/example.2025.18.
Bibliography	Patel, Imani. “Feedback Timing and Student Revision.” Journal of Learning Practice 18, no. 2 (2025): 133–52. https://doi.org/10.0000/example.2025.18.
Author-date citation	(Patel 2025, 144)
Reference list	Patel, Imani. 2025. “Feedback Timing and Student Revision.” Journal of Learning Practice 18 (2): 133–52. https://doi.org/10.0000/example.2025.18.

The DOI above is fictional and intentionally nonfunctional. Use the real DOI supplied by the article when one exists.

For a focused explanation of persistent identifiers versus ordinary web addresses, use DOI vs URL: Which Should You Use in a Reference? rather than copying a browser-session link into Chicago references.

Webpages and Online Content

Chicago’s current guidance allows some website content to be described in the text when a formal citation would add little value. When a formal note or final entry is needed, identify the page title, site owner or sponsor, publication or revision date when available, and URL. If no publication or revision date is supplied, an access date can be included. Chicago 18 also gives explicit guidance for citing archived versions of web pages when the live page has changed or disappeared.

Do not treat every file downloaded from a website as a webpage. A report remains a report, a journal article remains a journal article, and an e-book remains a book even when your browser is how you reached it. Classify the intellectual source before choosing the citation pattern.

Quotations, Page Numbers, and Other Locators

A note or author-date citation should identify the location of a direct quotation when the source provides a stable locator. For books and paginated articles, this is usually a page number or range. For unpaginated digital sources, a chapter, section, timestamp, paragraph number, figure number, or another useful locator may be more appropriate.

The decision to quote, paraphrase, or summarize comes before punctuation. Use quoting vs paraphrasing vs summarizing to choose the right source-use method, then apply the Chicago locator rule.

Do not invent page numbers for webpages, HTML articles, or e-books that do not provide stable pagination. The current Chicago Q&A also cautions against citing an unnumbered paragraph as “para. 1” if that numbering is not actually present in the source.

Bibliography vs Reference List

The final source list changes name with the system. Notes and bibliography normally ends with a bibliography. Author-date normally ends with a reference list. Both are usually alphabetized by the lead author, but the placement of the year and other punctuation differ.

For the cross-style mechanics of matching every in-text marker to its final source record, see how to create an academic reference list. In Chicago, apply that verification habit while preserving the correct label and format for your chosen system.

A bibliography can sometimes include works that informed the project even if they are not cited in individual notes, depending on the assignment. A reference list in author-date is normally tied closely to the works cited in the text. Follow your instructor’s scope requirement.

Chicago Style for Student Papers and Turabian

The Chicago Manual of Style is primarily written for professional authors, editors, and publishers. Students commonly use Turabian guidance, which adapts Chicago style for research papers, theses, and dissertations. The Chicago website’s Resources for Students explains that Turabian and Chicago use compatible Chicago-style citation formats and provides student-oriented tip sheets for footnotes, endnotes, parenthetical citations, bibliographies, and reference lists.

If your instructor says “Chicago/Turabian,” use the documentation system and paper-formatting details required for the assignment. Do not assume that a professional book-manuscript layout is automatically the correct student-paper layout.

A Practical 9-Step Chicago Citation Workflow

Confirm the system. Decide whether the assignment requires notes and bibliography or author-date. If it only says “Chicago,” check the rubric, course guide, or instructor preference.
Confirm the edition. Use Chicago 18 unless the course explicitly requires Chicago 17 or another legacy version.
Identify the source type. Decide whether the item is a book, chapter, journal article, webpage, report, thesis, video, social post, or another source before formatting it.
Capture source metadata. Record authors, title, container title, date, volume/issue, publisher, pages or article number, DOI/URL, and any relevant role such as editor or translator.
Insert the citation while drafting. Create the note or author-date citation at the point where the source enters your reasoning instead of postponing all citations until the end.
Add a precise locator when needed. Use the real page, chapter, section, timestamp, or another stable locator for quotations and close references.
Build the matching final entry. Create the bibliography or reference-list entry from the same source record.
Shorten repeated notes correctly. If using notes, change later citations to a clear shortened form rather than repeating full notes.
Audit the whole source trail. Check authors, dates, titles, italics, quotation marks, DOI/URLs, locators, note numbering, alphabetical order, and consistency with the chosen system.

Common Chicago Citation Mistakes

Using notes and bibliography in one section and author-date in another without an explicit reason.
Typing note numbers manually instead of using Word’s footnote/endnote function.
Copying a full note into the bibliography without changing name order and punctuation.
Repeating the full note every time instead of using a shortened note.
Using outdated Chicago 17 author-count or book-publication-place rules when Chicago 18 is required.
Putting a journal article’s database landing-page URL in place of an available DOI.
Forgetting that a bibliography and an author-date reference list place the year differently.
Treating a report, e-book, or journal article as a generic webpage because it was accessed online.
Inventing page numbers or paragraph numbers for unpaginated sources.
Using a citation generator without checking whether it is set to Chicago 18 and to the correct documentation system.

Chicago Citation Checklist Before Submission

Check	Question to ask
System	Am I using notes-bibliography or author-date consistently?
Edition	Does my course require Chicago 18, and is my citation tool set to that edition?
Source type	Did I format the actual source type rather than the website or database that delivered it?
Authors	Did I apply the current author-count rule?
Locators	Are quotation pages or other locators real and precise?
Repeated notes	Did I use a clear shortened form after the first full note?
Final list	Does every required source appear in the bibliography or reference list?
DOI/URL	Did I use a stable DOI or appropriate URL instead of a temporary session link?
Alphabetization	Are final entries ordered correctly?
Consistency	Do punctuation, italics, title treatment, and dates follow one Chicago system throughout?

Frequently Asked Questions

Does Chicago always use footnotes?

No. Chicago supports both notes and bibliography and author-date. Notes are central to the first system; author-date uses parenthetical citations and a reference list.

What is the current Chicago edition?

The Chicago Manual of Style is currently in its 18th edition, published in 2024.

Should I use a bibliography or a reference list?

Use a bibliography with notes and bibliography unless your assignment says otherwise. Use a reference list with author-date.

Can I use endnotes instead of footnotes?

Yes when the assignment or publication allows them. Both are note-based. Student instructions may specify one.

Do I still need a bibliography if I use footnotes?

Usually yes in a notes-and-bibliography paper, although some short assignments may allow notes alone. Follow the assignment.

Can I use “ibid.” in Chicago?

Chicago allows shortened citations in place of “ibid.” The regular author-title shortened form is clear and easy to maintain.

Does a book citation need the city of publication?

Not in ordinary Chicago 18 book citations. This is a common difference between current and older examples.

How many authors do I list?

In Chicago 18, notes and author-date text citations list up to two authors; three or more use the first author plus “et al.” Final bibliography/reference-list entries list up to six, and for more than six list the first three plus “et al.”

Can I use a citation generator?

Yes as a drafting aid. Confirm Chicago 18, choose the correct notes or author-date variant, and verify the output against the source and official Chicago guidance.

Is Turabian the same as Chicago?

Turabian adapts Chicago style for student research papers and uses compatible citation formats. Course-specific formatting directions still control the submission.