How to Write an Annotated Bibliography

An annotated bibliography is a list of sources in which each citation is followed by a short paragraph, the annotation, that summarizes the source and usually evaluates its credibility and relevance. It is written in a citation style such as APA, MLA, or Chicago, with entries arranged alphabetically by author.

What Is an Annotated Bibliography?

An annotated bibliography looks like a normal References, Works Cited, or Bibliography page, but each source is followed by a paragraph of your own writing. That paragraph — the annotation — tells the reader what the source says, how trustworthy it is, and why it matters. Instructors assign it to confirm you have actually read and judged your sources before drafting, which is why it is a common first step in a literature review or research project. Every entry has two parts: the citation (bibliographic details in APA, MLA, or Chicago) and the annotation (a 100–200 word paragraph that summarizes and usually evaluates the source).

What's the Difference Between Descriptive, Evaluative, and Reflective Annotations?

Annotations come in three types, and many assignments blend them. Check your prompt for which is expected.

How Do You Write an Annotated Bibliography?

1. Choose credible sources. Prioritize peer-reviewed, authoritative, and reasonably current works, and aim for a mix of foundational and recent sources so your bibliography shows range (see how to judge source quality).
2. Write the citation. Format each source in your assigned style with a hanging indent, and get the author, date, title, and publication facts exact — the citation is the part readers actually verify.
3. Summarize the source. In 2–3 sentences and your own words, state its main argument, scope, method, and key findings. Never paste the published abstract — that is not an annotation.
4. Evaluate it. Assess the author's authority, the strength of the evidence or methodology, any bias or limitation, and how the source compares with others on your list.
5. Format and reflect. Add a sentence on how the source supports your thesis or project, then alphabetize every entry by the first author's surname and check the spacing rules for your style.

How Do You Format an Annotated Bibliography in APA, MLA, and Chicago?

The annotation reads the same in every style; only the citation format changes.

Always confirm the exact indentation and spacing against your instructor's requirements or the official handbook — these details vary by course. Chicago also offers an Author-Date system as an alternative to the Notes-Bibliography style shown here.

What Does an Annotated Bibliography Entry Look Like?

Here is the same source — Anne Lamott's Bird by Bird — as a full entry in each style. Only the citation line changes; the annotation stays the same. The colored labels mark the citation, the summary, and the evaluation.

Note: recent Chicago editions make the city of publication optional — “New York:” may be omitted.

What Are Common Annotated Bibliography Mistakes?

• Only summarizing when the assignment wants evaluation.
• Copying the abstract instead of writing the annotation yourself (risks plagiarism).
• Mixing citation styles — pick one and apply it consistently.
• No hanging indent or wrong order — alphabetize and indent.
• Annotations too long or too short — aim for ~100–200 words.

Conclusion

An annotated bibliography is simple once you separate its two jobs: cite the source correctly, then summarize and evaluate it in a focused paragraph. Get the format right for your style — see our APA citation guide, MLA citation guide, and Chicago/Turabian guide — keep annotations evaluative, and alphabetize your entries.