Chicago Style Citation in 2026: Notes-Bibliography vs Author-Date (Copy-Paste Examples)

Every time a history student drops a footnote and a sociology student drops a parenthetical, they are both using Chicago style citation — yet their papers look nothing alike. The Chicago Manual of Style (CMOS) offers two separate documentation systems, and choosing the wrong one for your discipline is one of the most common formatting errors instructors flag at the citation stage. This guide covers both systems with exact, copy-paste-ready examples updated for CMOS 18th edition (2024), the latest release from the University of Chicago Press.

Whether your assignment requires the Notes-Bibliography format with footnotes or the Author-Date format with parenthetical citations, you will find complete templates here for books, journal articles, book chapters, and websites — plus a plain-English explanation of when ibid. is still acceptable and what changed between CMOS 17 and CMOS 18.

What Is Chicago Style? (CMOS 18th Edition)

The Chicago Manual of Style is published by the University of Chicago Press and is now in its 18th edition (2024). It is the dominant style guide for book publishers, many humanities journals, and university presses across the United States and beyond. Students writing theses or dissertations often use Kate Turabian’s A Manual for Writers of Research Papers, Theses, and Dissertations (9th ed., University of Chicago Press, 2018), an officially recognised student adaptation of CMOS. Both sources are aligned on every citation format covered in this guide.

The most significant change from CMOS 17 to CMOS 18 is the removal of the place of publication requirement for books. Under CMOS 18, you no longer need to list the city (e.g., “New York:”) before a publisher’s name. You may still include it where it helps distinguish between publishers with similar names, but it is no longer mandated. All examples below follow CMOS 18.

Which System Should You Use?

The short answer: ask your instructor. If no guidance is given, your subject area is the clearest signal:

Notes-Bibliography: Footnotes, Shortened Notes & Ibid.

In the NB system, every time you quote, paraphrase, or summarise a source, you insert a superscript number in your text and a corresponding note at the bottom of the page (footnote) or at the end of the document (endnote). A bibliography lists all sources alphabetically at the end of the paper or chapter.

Full Notes vs Shortened Notes

The first note for any source uses the full citation — author firstname-first, full title, publication details, and page number. All subsequent notes for the same source use a shortened form: author surname, an abbreviated title (if the title runs to more than four words), and a page number. You never repeat full publication details a second time.

• Full note format: Firstname Lastname, Title of Book (Publisher, Year), page.
• Shortened note format: Lastname, Short Title, page.

Note the key structural difference from bibliography entries: in footnotes, the author’s name is given firstname-last and elements are separated by commas. In the bibliography, the name is inverted (Lastname, Firstname) and elements are separated by periods. This distinction trips up many students who copy their bibliography entries directly into footnotes.

Ibid.

Ibid. (from the Latin ibidem, “in the same place”) may be used when a footnote cites the immediately preceding source at the same page. CMOS 18 acknowledges ibid. as acceptable but mildly discourages it, since numbered shortened notes are easier to follow in digital documents with hyperlinked footnotes. The rules:

• Same source, same page: write simply Ibid.
• Same source, different page: write Ibid., 47.
• If any other source intervenes between two citations of the same work, ibid. cannot be used — use the shortened note instead.

Many university style sheets still permit ibid. freely. Check your department guide before abandoning it.

Copy-Paste Examples: Notes-Bibliography

All examples below follow CMOS 18. Place of publication is omitted from book citations. Titles of books and journals are italicised; article and chapter titles appear in quotation marks.

Books

Journal Articles

Chapter in an Edited Book

Websites

For web sources, include the author or organisation, the page title in quotation marks, the site name, the date published or last modified (if available), and the URL. When no date is given, add an access date at the end: “accessed June 23, 2026.”

Author-Date: In-Text Citations & Reference List

The Author-Date system is structurally similar to APA 7 — both use parenthetical citations and a reference list — but differs in several details. The in-text pattern is (Lastname Year, page). When the author’s name appears in the running sentence, the parenthetical reduces to (Year, page): “Kwon (2022, 812) argues that…”

The single most visible structural difference in the reference list is the position of the year: in Author-Date, the year moves immediately after the author’s name, separated by a period. In the NB bibliography, the year appears near the end of the citation, in parentheses after volume/issue information. Everything else — alphabetical order by surname, inverted name, italicised book and journal titles — stays the same.

Unlike a bibliography, a reference list contains only sources cited in the text. No additional consulted-but-not-cited works are included.

Copy-Paste Examples: Author-Date

Books

Journal Articles

Chapter in an Edited Book

Websites

NB vs AD: Side-by-Side Comparison

Common Chicago Citation Mistakes to Avoid

• Copying bibliography format into footnotes. Footnotes list the author firstname-first with commas between elements. Bibliographies invert the name and use periods. These are structurally different entries — never paste one into the other’s place.
• Omitting page numbers in footnotes. Unlike bibliographies, footnotes almost always require a specific page or page range. “Kwon 2022” alone is not a complete footnote in either Chicago system.
• Mixing NB and AD in one paper. Pick one system and apply it throughout. Switching mid-paper is an automatic style violation.
• Leaving out the DOI. CMOS 18 expects DOIs for journal articles when one exists. Always include it if the article has one.
• Over-using ibid. If a reader skips directly to a footnote and sees “Ibid., 23,” they cannot identify the source without reading backward through every preceding note. Reserve ibid. for truly consecutive citations where locating the previous note is immediate.
• No access date for undated websites. When a website provides no publication or modification date, add “accessed [Month Day, Year]” after the URL.

If you need to decide how many sources to cite overall, our guide to how many references a thesis should have provides discipline-by-discipline benchmarks. For parallel formatting decisions in APA, the step-by-step APA 7 formatting guide covers in-text and reference-list rules in the same example-rich format. Our Harvard Referencing Guide and MLA 9 format guide complete the picture for the other two styles most commonly required in humanities and social-science programmes.

For additional Chicago examples covering conference proceedings, government documents, and legal sources, the complete walk-through at tesify.app’s Chicago citation style guide extends both systems into less common source types.

Frequently Asked Questions