How to Write an Annotated Bibliography in Chicago Style

A Chicago annotated bibliography is a normal Chicago bibliography with a paragraph of commentary attached to each entry. Write every entry exactly as section 13.68 of the Chicago Manual of Style, 18th edition, expects a bibliography entry to look, keep the list alphabetical, and then place the annotation in one of the two ways the manual allows: run in directly after the entry, or on a new line below it.

Everything else on the page (heading, spacing, how long each annotation runs) comes from your instructor's assignment sheet, because the manual leaves it open. This guide covers both parts: the rules Chicago fixes and the choices it leaves to you, with seven worked entries you can model.

What Chicago 18th edition actually says

The 18th edition (2024) treats the annotated bibliography as one of several kinds of bibliography a writer can build, alongside a full bibliography of every work consulted and a selected one. The rule that matters for students is in section 13.68, and the University of Alberta Library's annotated bibliography guide summarizes its two layout options:

1. Put each annotation directly after the citation, without starting a new paragraph. The annotation may also be enclosed in brackets.
2. Start each annotation on a new line. You may indent it from the left margin.

That is the whole layout rule. The manual does not set a word count, does not say whether the annotation must evaluate or only summarize, and does not prescribe an indent measurement. Those decisions belong to whoever set the assignment.

The entries themselves follow the standard notes-bibliography format from chapter 13 and the examples in chapter 14. A few rules from the 18th edition change how those entries look compared with the 17th, and they show up in annotated bibliographies constantly:

• Repeated authors. The 18th edition no longer recommends the 3-em dash for a second work by the same author. Repeat the name instead (section 13.72, as the University of Queensland Library's Chicago 18th bibliography guide notes).
• Many authors. List up to six authors in a bibliography entry. For seven or more, list the first three followed by et al. (sections 13.23 and 13.78).
• Place of publication. It is no longer required for books published since 1900 (section 14.30).
• Chapter page ranges. A chapter in an edited book no longer needs its page range in the bibliography entry (section 14.9). Journal articles still need theirs.
• DOIs. Format them as URLs beginning https://doi.org/ (section 13.7).

The University of Portland's summary of what changed in the 18th edition lists each of these with its section number, and it is a good page to keep open while you write.

Two ways to place the annotation

Both layouts are correct under 13.68. Pick one and use it for every entry in the list.

Option 1: run-in annotation

The annotation continues on the same line as the bibliography entry, after the final period. This is compact and suits short annotations of one to three sentences.

Kuhn, Thomas S. The Structure of Scientific Revolutions. University of Chicago Press, 1962. Kuhn argues that science advances through periods of normal research inside an accepted paradigm, punctuated by revolutions in which the paradigm itself is replaced. The book is the usual source for the term "paradigm shift."

The bracketed variant puts the same text inside square brackets:

Kuhn, Thomas S. The Structure of Scientific Revolutions. University of Chicago Press, 1962. [Kuhn argues that science advances through periods of normal research inside an accepted paradigm, punctuated by revolutions in which the paradigm itself is replaced.]

Brackets make the boundary between citation and commentary obvious when the annotation is short. They get awkward past two sentences.

Option 2: annotation on a new line

The bibliography entry keeps its hanging indent. The annotation starts on the next line as its own paragraph, and the manual allows you to indent the whole annotation from the left margin.

Kuhn, Thomas S. The Structure of Scientific Revolutions. University of Chicago Press, 1962.

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Kuhn argues that science advances through periods of normal research inside an accepted paradigm, punctuated by revolutions in which the paradigm itself is replaced. He draws most of his cases from physics and chemistry, including the Copernican and chemical revolutions. The argument is historical and philosophical rather than statistical, so it supports claims about how scientists reason more than claims about how often paradigms change.

This is the layout most university assignment sheets show, and it is the one to use if your annotations run to a full paragraph or more. When the manual says you "may" indent, it gives no measurement. Most students align the annotation with the hanging indent of the entry above it, 0.5 inch in a standard word-processor setup, so the commentary visually belongs to its citation. If your instructor's sample shows a different indent, copy the sample.

Page setup

The manual governs the entries. The page around them follows Chicago's general manuscript conventions, which the Purdue OWL's Chicago 18th general format page summarizes:

• Heading. Center the title at the top of the first page. Use "Annotated Bibliography" when the assignment is the list itself; a list attached to a paper in notes-bibliography style is usually headed "Bibliography."
• Spacing. Body text is double-spaced, but bibliography entries are an exception. Purdue's version: leave two blank lines between the heading and the first entry, then one blank line between entries, with each entry single-spaced inside.
• Hanging indent. The first line of each entry sits at the left margin, and every following line indents. Our guides to setting one in Microsoft Word and Google Docs walk through the menus.
• Margins and font. At least 1-inch margins, a readable font such as Times New Roman, 12 point preferred.
• Page numbers. In the header, starting at 1 on the first page of text.

A lot of instructors override the spacing rule and ask for double spacing throughout, annotations included, because it leaves room for comments. If the assignment sheet says double-space everything, do that. The sheet outranks the general Chicago default for a class paper.

Worked examples

Each example below uses notes-bibliography format with the annotation on a new line, the layout most assignments ask for. The sources are real and checkable.

1. A book by one author

Kuhn, Thomas S. The Structure of Scientific Revolutions. University of Chicago Press, 1962.

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Kuhn argues that scientific fields move between long stretches of "normal science," in which researchers solve puzzles inside a shared framework, and short revolutionary periods in which that framework is abandoned for a new one. His cases come mostly from the physical sciences. The book is the standard starting point for any paper on how scientific consensus forms, though readers in the social sciences should note that Kuhn built his model on fields with a single dominant paradigm.

No place of publication appears, because the book was published after 1900. A 17th-edition entry would have read "Chicago: University of Chicago Press, 1962." Either is still recognizable, but the 18th edition dropped the city.

2. A journal article with two authors

Tuck, Eve, and K. Wayne Yang. "Decolonization Is Not a Metaphor." Decolonization: Indigeneity, Education & Society 1, no. 1 (2012): 1-40. https://jps.library.utoronto.ca/index.php/des/article/view/18630/15554.

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Tuck and Yang argue that decolonization specifically means the return of stolen Indigenous land, and that applying the word to any social justice project empties it of that meaning. They catalogue six "settler moves to innocence," strategies by which settlers acknowledge colonialism while avoiding its material consequences. The article sets a strict definition that is useful for separating decolonial claims from multicultural or inclusion-based ones in other sources.

Only the first author is inverted. The second author's name stays in normal order, and "and" joins them. The article title uses headline-style capitalization, so "Is" is capitalized even though the journal's own page may print it lowercase.

3. A chapter in an edited book

Battle, Ken. "Child Poverty: The Evolution and Impact of Child Benefits." In A Question of Commitment: Children's Rights in Canada, edited by Katherine Covell and R. Brian Howe. Wilfrid Laurier University Press, 2007.

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Battle traces how Canada's federal child benefits developed and assesses their effect on child poverty, drawing on government documents and leaning heavily on his own earlier policy work. The chapter is a compact overview of income support for families with children. Because so much of the evidence is the author's own prior analysis, pair it with an independent study before relying on its conclusions.

This entry shows two 18th-edition changes at once. The chapter's page range is gone (older samples of this same chapter print "21-44"), and so is the place of publication. The editors' names appear in normal order after "edited by."

4. A journal article where the dataset matters

Kerr, Don, and Roderic Beaujot. "Child Poverty and Family Structure in Canada, 1981-1997." Journal of Comparative Family Studies 34, no. 3 (2003): 321-35.

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Kerr and Beaujot examine Canadian child poverty from 1981 to 1997, breaking the rates down by family structure, parental age, and family size. The article pairs well with Battle's chapter: Battle evaluates the policy response, and Kerr and Beaujot measure the problem it responded to.

An evaluative sentence that links two sources in the list is one of the most useful things an annotation can do. It shows the reader you read both and know how they fit together.

5. A web page from an organization

"Chicago Style Q&A: Now Updated." CMOS Shop Talk, September 29, 2026. https://cmosshoptalk.com/2026/09/29/chicago-style-qa-now-updated/.

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The Chicago Manual of Style's editorial blog announces that its online Q&A archive now refers to the 18th edition throughout, with updated paragraph numbers and editor's notes on answers whose guidance changed. Useful as evidence that Q&A answers dated before 2024 may cite superseded 17th-edition rules.

The post carries no personal author, so the entry begins with the title, and it is alphabetized under C, the first word that is not an article. The Purdue OWL's Chicago web sources page gives the full pattern: author if there is one, title in quotation marks, site name, publisher if different from the site, date, and URL. When a page has no date at all, an access date goes before the URL.

6. Two books by the same author

Kuhn, Thomas S. The Essential Tension: Selected Studies in Scientific Tradition and Change. University of Chicago Press, 1977.

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[annotation]

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Kuhn, Thomas S. The Structure of Scientific Revolutions. University of Chicago Press, 1962.

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[annotation]

The name repeats in full on the second entry. The 17th edition replaced it with a 3-em dash (a rule three em dashes long, followed by a period), and many older sample bibliographies still show one. Order the two works by title (section 13.70), ignoring an initial "The" (section 13.100), so Essential sorts before Structure even though both titles begin with "The."

7. A work with seven or more authors

The pattern, with placeholder names:

Lastname, Firstname, Firstname Lastname, Firstname Lastname, et al. "Article Title." Journal Name volume, no. issue (Year): pages. https://doi.org/xxxxx.

List the first three authors, then et al. For a work with exactly six authors, list all six. The 17th edition's threshold was different, so check this one in any entry a generator or older template produced.

Writing the annotation itself

The manual governs where the annotation sits. What goes in it is a research task, and most assignments ask for some mix of three things.

Summary. What the source argues and how. Name the method or evidence type, such as archival documents or interviews. One or two sentences is enough for most sources.

Evaluation. How strong the argument is, and for whom. Note the author's position (Battle leans on his own earlier policy analysis), the scope of the evidence (Kuhn's cases are mostly physics and chemistry), or how old the data is.

Relevance. What the source does for your project. This is the part instructors read most closely, because it shows you have a plan for the source and did not collect it at random.

A descriptive annotation stops after the summary. An evaluative or critical annotation includes all three. If the assignment sheet uses either word, that tells you which one it wants. Our general guide to annotated bibliographies compares the three annotation types across APA, MLA, and Chicago.

Length is set by the instructor. Library guides commonly suggest 100 to 200 words, and nothing in the manual contradicts or confirms that. Write in full sentences, in your own words. A direct quotation inside an annotation needs quotation marks, and most instructors expect a page reference with it.

Notes-bibliography or author-date

Chicago has two citation systems, and an annotated bibliography can use either. Your discipline usually decides. History and the humanities mostly use notes-bibliography; the sciences and social sciences more often use author-date, where the list is headed "References" and the year moves up behind the author's name.

The same article in author-date format:

Tuck, Eve, and K. Wayne Yang. 2012. "Decolonization Is Not a Metaphor." Decolonization: Indigeneity, Education & Society 1 (1): 1-40. https://jps.library.utoronto.ca/index.php/des/article/view/18630/15554.

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[annotation]

The two differences to watch: the year follows the authors, and the issue number goes in parentheses after the volume. The annotation rules from 13.68 apply unchanged. Our guide to Chicago author-date covers in-text citations for this system, and the notes-bibliography guide covers footnotes.

Special cases

No author

Start with the title and alphabetize by its first word other than "a," "an," or "the." If an organization takes responsibility for the page and no person is named, use the organization as the author instead.

No date

For a web page with no publication or revision date, give the date you accessed it, in the form "Accessed October 17, 2026," immediately before the URL. For a printed work with no date, use "n.d."

A paper with an annotated bibliography attached

Some assignments pair a short paper with an annotated bibliography. The paper still uses footnotes. Because a bibliography is present, the 18th edition allows the first note for each source to be a shortened note (author, short title, page) rather than a full one. The bibliography carries the full details, and the annotation follows each entry there. Footnotes never carry the annotation.

The source is in a language other than English

Give the title in the original language, capitalized according to that language's conventions, and add an English translation in square brackets after it if your reader may need one. Write the annotation in English unless the assignment says otherwise.

Your class uses Turabian

Turabian's A Manual for Writers adapts Chicago style for student papers. The 9th edition (2018) was built on the 17th edition of the Chicago Manual, so a class that specifies Turabian 9 may still expect the 3-em dash and places of publication. Ask which edition the course follows, then apply that edition's entry rules. The 13.68 annotation layouts work for either.

Grouping entries by category

Long annotated bibliographies sometimes split sources into sections: primary and secondary sources, or one section per theme. Chicago permits a divided bibliography. Alphabetize within each section, and give each section a subheading.

Common mistakes and how to avoid them

Formatting entries as footnotes. A footnote puts the author in normal order and separates elements with commas and parentheses. A bibliography entry inverts the first author and separates elements with periods. Annotated bibliography entries are always in bibliography form.

Mixing the two layouts. Some entries run in and some start a new line, usually because annotations were written at different times. Pick one layout and convert the rest.

Keeping 17th-edition habits. Publisher cities, chapter page ranges, and the 3-em dash all come from older templates and older generators. The Chicago 18 generator checklist lists the places stale output hides.

Sorting by the annotation's subject. The list is alphabetical by the first word of each entry, regardless of topic, unless the assignment asks for categories.

Writing only a summary when the sheet says "evaluative." An evaluative annotation that never says how strong or limited the source is will lose marks. Add one sentence on the evidence or the author's position.

Losing the hanging indent in the annotation. When the annotation sits on its own line, apply the hanging indent to the entry only. If the annotation inherits the hanging indent, its first line sits at the margin and the rest indents, which reads as a second citation.

Quick-reference table