How to Format Headings and Subheadings in APA, MLA, and Chicago

How to Format Headings and Subheadings: Quick Answer

Pick the assigned handbook first. Start at the top of that handbook's ladder and never skip a rank. Do not open an APA paper with the word Introduction. Keep MLA internals flush left. In Chicago work, decide whether the course still wants Turabian 9 / CMOS 17 headline style or CMOS 18 title case — they no longer treat long prepositions the same way.

The first sentence is the APA Style headings page (Publication Manual §2.27), reprinted verbatim on 15 September 2026 by the University of Delaware APA paper-format guide (“All information taken from: APA Style Website”). The second is the MLA Style Center note opened the same day. The third is CMOS Shop Talk. The fourth is the live CMOS 18 What's New line for §2.65.

Choose the Style Before You Format a Heading

Most heading errors are style-mismatch errors. Students paste a centered bold APA Level 1 into an MLA essay, or they label the opening Introduction because every outline they have seen starts that way. The first decision is not font size. It is which handbook owns the paper.

1. Read the assignment. If the prompt names APA, MLA, Chicago, Turabian, IEEE, or a journal template, that document wins over any generic advice — including this page.
2. If the prompt is silent, follow the discipline default. Psychology, education, nursing, and most social sciences use APA. Literature, languages, and many humanities courses use MLA. History and some other humanities courses use Chicago or Turabian.
3. Ask which Chicago book. Turabian 9 still follows CMOS 17. CMOS 18 (2024) changed title case. A heading that lowercases About is Turabian 9 / CMOS 17; a heading that capitalizes it is CMOS 18.
4. Decide whether headings are even warranted. Short essays often read better without them. MLA is explicit that headings should not paper over a thin argument. Turabian lets you mark a break with three spaced asterisks instead.
5. Apply that style's hierarchy from the top down. Start at Level 1 (or the paper title, in APA and MLA). Do not skip a level, and do not invent a sixth look.

What a Heading Is For

A useful heading does four jobs at once. It outlines the paper for a skimming reader, it marks a genuine turn in the argument, it gives screen-reader users a jump list, and it keeps you honest about whether a section has a job. If a heading could sit on any paper in the course (Analysis, Background, Discussion of Findings), rewrite it until it names this paper's claim. IMRAD labels in APA science papers are the exception: the student-paper setup guide tells you to “Use descriptive headings to identify other sections (e.g., Method, Results, Discussion for quantitative research papers).” Those conventional nouns are the contract, not decoration.

APA 7th Edition: Five Prescribed Levels

APA is the only major student style that tells you exactly how each level looks. The APA Style headings page covers Publication Manual §§2.26–2.27 (Concise Guide §§1.25–1.26). The live PDFs are easier to quote because the HTML page is often behind a bot challenge: the heading-levels template (last updated 21 March 2022; cites Table 2.3, Figure 2.4, and Figure 2.5) and the student-paper setup guide (last updated 8 October 2025). Use only as many levels as the paper needs, always starting at Level 1. If you need one level, use Level 1; if you need two, use Levels 1 and 2; if you need three, use 1, 2, and 3. The official template's own average is three. Levels 4 and 5 are for long Method sections, not for a five-page response paper.

The Level 3 mistake is the one this page used to teach. Level 3 is not a run-in heading and it does not take a period. Only Levels 4 and 5 are indented, end with a period, and continue as ordinary paragraph text. If your "Level 3" looks like a bold sentence at the start of a paragraph, you have formatted a Level 4. APA 6 did use a run-in Level 3; APA 7 moved that look down one rank.

The paper title is the first Level 1 heading

Two official APA sentences say the same thing in slightly different words. Keep both; instructors quote either PDF or the headings page:

Repeat the full paper title at the top of the first text page, centered and bold, in title case. Start the opening paragraph on the next double-spaced line. If the introduction itself needs subsections, those start at Level 2. After the introduction, the next main section — Method, Results, Discussion, Literature Review — is a new Level 1 heading. A professor who explicitly requires the word Introduction overrules the handbook; the setup guide says “Instructors’ guidelines supersede APA Style.”

Worked APA example (official heading-template labels)

The labels below are the heading-levels template's own demonstration strings, not a study title. The template also tells you that a paper with Level 1 Method, Results, and Discussion headings may give Method and Results two subheading levels (2 and 3) while Discussion has only Level 2 — each section still starts at Level 1.

The last sentence is the setup guide's line-spacing rule (8 October 2025), not the heading template. A typical Method block is still Method (Level 1) with Participants, Materials, and Procedure (Level 2). Add Level 3 only when a Level 2 section is long enough to split. The setup guide's final-check line is the same outline test: “Avoid having only one subsection within a section (have two or more, or none).”

Student papers versus professional manuscripts

The five heading levels are the same in student and professional APA papers. What changes is the chrome around them. Student papers usually omit a running head; professional papers include one. Abstracts, keywords, and author notes appear when the venue asks for them, not because headings exist. APA publishes printable student and professional heading-level templates, plus the student-paper setup guide. Download the APA 7 paper template if you want the page geometry already set, then apply heading styles rather than restyling each line by hand.

MLA 9th Edition: A Consistent Flush-Left System

MLA does not ship a five-level table. The MLA Style Center (opened 15 September 2026; published 13 December 2018) and MLA Handbook §1.5 ask you to build a small, consistent system and to skip headings entirely in a short essay. The advice that MLA headings must be centered, unbolded, and never numbered is a campus myth. Official MLA guidance says the opposite on two of those three points.

The rest of the official system is small enough to memorize:

• The paper title is Level 1 and must be the most prominent heading on the page. Center it. Do not bold it unless your instructor says otherwise.
• Internal headings are flush left. Centering a section title in the body makes it look like a block quotation.
• Signal rank with type, not with position. The Style Center says a boldface, larger font indicates prominence; a smaller font, italics, and lack of bold can signal subordination. Do not use all capitals.
• Leave a line space above and below a heading. MLA wants that extra air; APA's setup guide forbids it.
• Generally avoid numbered or lettered heads unless the discipline expects them. If you label one heading 1, you owe the reader a 2.
• No internal level may appear only once, except the title and the headings for notes and the works-cited list.
• Capitalize headings like the titles of works (MLA Handbook §1.5).
• You should also generally have text under each heading.

Official MLA illustration, then a labelled template

The Style Center illustrates rank with three generic lines. Those words are the official sample, not a literature-paper outline:

A longer literature essay can then apply that same flush-left ladder to content headings. The lines below are a labelled template, not a published essay:

That hierarchy is a recommendation built from the Style Center's prominence rule, not a mandated MLA table. What the handbook will mark wrong is inconsistency: one Level 1 in bold 14-point and the next in centered italics. Pick a system, write it down at the top of your draft, and reuse it. The MLA 9 paper template sets margins and the first-page heading; it does not invent section heads for you.

Chicago 18 and Turabian 9: Two Books, One Family

The Chicago Manual of Style 18th edition is a publishing handbook. It does not give student papers a required heading table. CMOS 18 §2.65, as the What's New list states it, allows either title case or sentence case for subheads as long as each level is consistent. For class papers, theses, and dissertations, Turabian, A Manual for Writers (9th ed.) is still the student interface, and its student tip sheets remain “fully compatible with The Chicago Manual of Style (17th ed.).” Turabian 10 is announced for late 2026 — some catalogs list 8 October 2026, others 24 November 2026 — and it is not yet the live classroom handbook. See Turabian vs Chicago.

If the paper has only a few sections, Turabian lets you skip named subheads and put three spaced asterisks (* * *) on their own centered line. When you do want a full ladder, Appendix A.2.2.4 offers this optional five-level plan (Turabian 9, p. 404). It is a model, not a law; a department template that contradicts it wins. The George Fox Turabian 9th ed. guide (last updated 22 September 2021) reprints those ranks and adds the campus reminder that Turabian “does not require any specific heading style.”

Chicago and Turabian put more space before a subhead than after it. Do not close a page on a heading. Do not put a period on Levels 1–4. In Turabian 9 / CMOS 17, headline-style capitalization applies to Levels 1–3 and lowercases prepositions of any length. CMOS 18 now calls that system title case and capitalizes prepositions of five letters or more. Levels 4–5 stay sentence case in the Turabian plan — the opposite of APA's all-title-case ladder.

Worked Turabian example (official Shop Talk capitalization pair)

Turabian does not reprint a required sample outline. CMOS Shop Talk does reprint the two capitalization looks. Use those official strings for the case difference; the alignment notes are the A.2.2.4 ranks, not a real chapter title.

APA vs MLA vs Chicago at a Glance

Numbered systems belong to other handbooks. The IEEE Editorial Style Manual for Authors uses four enumerated ranks. AMA and many Vancouver medical journals number sections in their own templates. If the assignment is IEEE or AMA, do not borrow APA's centered Level 1 and do not borrow MLA's unnumbered flush-left essay heads. Use the society template.

Title Case Is Not One Rule

"Use title case" is incomplete advice. APA, MLA, and Chicago agree on the first and last words and on capitalizing nouns, verbs, adjectives, adverbs, and pronouns. They disagree on mid-title prepositions — and CMOS 18 moved.

APA's title-case page treats every word of four letters or more as a major word, so With, From, Into, and After are capitals even though they are prepositions. MLA capitalizes headings like the titles of works and lowercases prepositions regardless of length. CMOS 17 and Turabian 9 headline style also lowercased prepositions of any length. CMOS 18 §8.160 now capitalizes prepositions of five letters or more and keeps four-letter ones lowercase, which is why the official pair is A Room with a View but Much Ado About Nothing.

The word that now gives the system away is about (five letters). APA and CMOS 18 capitalize it. MLA and Turabian 9 leave it lowercase. With (four letters) is still the older tell: APA capitalizes it; MLA, Turabian 9, and CMOS 18 all leave it lowercase. Hyphenated major words are capitalized on both sides in APA (After-School, Self-Report); CMOS 18 §8.162 now also capitalizes the second element after a prefix (Anti-Intellectual). Articles (a, an, the) and short conjunctions (and, but, or, nor) stay lowercase in all three student systems unless they are the first or last word or, in APA, the first word after a colon, em dash, or end punctuation. Run a draft heading through the title-case converter set to the assigned style; do not trust a generic "Title Case" button.

Write Headings That Can Stand Alone

Prefer a specific noun phrase to a generic label

APA's conventional Method / Results / Discussion labels are an exception: those words are the IMRAD contract, and swapping them for creative synonyms makes a science paper harder to search. Everywhere else, a heading should name the content.

Keep siblings parallel

Headings at the same level should share a grammatical shape. Mixing a gerund, a noun phrase, and a full clause makes the outline look unfinished. MLA is explicit that parallel structure helps readers grasp the project as a whole.

Stay short enough to scan

MLA's length rule is one sentence:

A heading is a signpost, not an abstract. If you need a clause with that or which, the idea belongs in the first sentence of the section. Aim for a few words, not a character limit. "An Examination of the Various Methodological Approaches Employed in the Present Study" is a title, not a heading.

Hierarchy Rules Shared by Every Style

Never skip a level

If the current heading is Level 1, the next deeper heading is Level 2, not Level 3. APA states this as a mechanical rule. MLA and Turabian reach the same place through prominence: each step down should look less marked than the one above it. Skipping a level is also an accessibility failure. The W3C heading tutorial asks for nested headings in logical order so a screen-reader user can jump without a missing rung:

Do not leave a level with only one child

APA, MLA, and Turabian all use the outline test: a Roman-numeral section that has an A must also have a B. One lonely subheading means the split is not a split. Either write the sibling section or promote its sentences back into the parent. The exceptions MLA names are the paper title and the headings for notes and the works-cited list. CMOS Shop Talk makes the same logic point. APA's heading template says it as an outline: “Use at least two subsection headings within a section or use no subsection headings at all.”

Keep the heading with its first lines

Turabian is blunt: never end a page with a subhead. APA's double-spacing rule has the same practical result — if a heading is stranded at the bottom of a page, move it. The heading template even says it is “not necessary to add blank lines before or after headings, even if a heading falls at the end of a page”; that is a spacing rule, not permission to leave an orphan. In Word, turn on "Keep with next" on heading styles so a heading cannot separate from the paragraph it introduces. In Google Docs, insert a page break before the heading rather than leaving it orphaned.

How many levels does this paper need?

• Under ~5 pages, or a single-claim essay: usually none. MLA and Turabian both warn against headings that disguise a missing structure. APA's heading template says short student papers may not require any headings.
• 5–12 pages with two or three movements: one level (APA Level 1; MLA flush-left internals; Turabian Level 1).
• IMRAD report, literature review, or chapter: two levels. APA's official average is three levels for a full research paper; two is still the default for most college reports.
• Thesis or multi-experiment Method section: three levels. Add a fourth or fifth only when a subsection is still too long to scan.

Use Real Heading Styles, Not Fake Bold

The APA setup guide's heading-format tip is to “Create heading styles using your word-processing program.” Screen readers, PDF tags, and Google Docs' document outline all read Heading 2 as a heading and read hand-bolded 12-point Times as ordinary text. A paper that looks hierarchical can still be a flat H1 soup. For Level 4 and 5 run-in heads, type the heading plus a few words of the paragraph, highlight only the heading, and apply the style so the rest of the sentence stays body text.

1. Map the word processor's Heading 1–5 styles to the style-guide levels you are actually using. In APA, Heading 1 = centered bold title case; Heading 3 = flush-left bold italic; Heading 4 = indented bold run-in with a period.
2. Apply those styles from the menu (Word, Google Docs). Do not select a line and impersonate a heading.
3. Check the navigation pane (Word) or document outline (Docs). Every section you think is a heading should appear there, in order, with no skipped rank.
4. Export to PDF only after the outline is clean. A tagged PDF inherits those heading levels; a print-to-PDF of fake bold does not.

The same outline is a drafting tool. Build the heading tree before the paragraphs, the way you would build an essay outline. If two Level 2 headings say the same thing, or if a Level 3 has no sibling, fix the structure before you write the section. How to Write a Research Paper and How to Write a Methodology are the places to decide what the sections contain; this page is the place to name and nest them.

IEEE Headings Are a Different Ladder

If the assignment is an IEEE Transactions paper, stop using APA or MLA heading looks. The official IEEE Editorial Style Manual for Authors (opened 15 September 2026) specifies four enumerated ranks. Enumeration is desirable but not required; the choice must be consistent. Introduction, Conclusion, and Acknowledgment are singular heads. References and Acknowledgment are never numbered. These are the manual's own examples:

Discipline Defaults

Sciences and social sciences (usually APA)

Keep the IMRAD nouns. Method (APA still accepts the singular), Results, and Discussion are Level 1. Under Method, Participants or Sample, Materials or Measures, and Procedure are Level 2. A preregistered study may add Transparency and Openness or Data Availability as Level 1 or 2, depending on the journal. Do not rename Results to What We Found.

History and other Chicago fields

Content headings outperform methodological ones. A chapter that names the event or archive is more useful than Analysis of Primary Sources. Primary-source subsections can sit at Level 2 or 3. If the paper is short, Turabian's three asterisks are cleaner than a single decorative heading. Confirm whether the course still wants Turabian 9 headline style or CMOS 18 title case before you capitalize About. See the history citation guide for the notes-bibliography side of the same papers.

Literature and languages (usually MLA)

Most short close readings need no internal headings. A longer essay can follow the argument rather than a research-methods skeleton. Italicize a work's title inside a heading the same way you would in a sentence. If the heading style is already italic, do not stack a second italic on the title; shorten the heading and put the full title in the first sentence.

Mistakes This Page Should Stop

Heading Checklist

Official Sources

Handbook pages change more slowly than blog posts. When a professor, a journal, and a website disagree, the assigned edition of the handbook wins.

Handbook and accessibility references

• APA Style: Headings (7th ed., §§2.26–2.27)
• APA heading-levels template: student paper (21 March 2022)
• APA student-paper setup guide (8 October 2025)
• APA Style: Title-case capitalization
• University of Delaware reprint of the APA headings page
• MLA Style Center: Styling headings and subheadings
• CMOS Shop Talk: Turabian/Chicago sections and subheads
• CMOS 18: What's New (§2.65, §8.160, §8.162)
• Turabian: A Manual for Writers (student Chicago)
• Turabian student paper-formatting tip sheets
• George Fox reprint of Turabian 9 p. 404 heading ranks
• IEEE Editorial Style Manual for Authors (section headings)
• W3C: Headings (page structure and accessibility)

Related guides and tools

• How to Format an Academic Paper
• Turabian vs Chicago
• How to Write an Introduction
• How to Write a Research Paper
• How to Write a Methodology
• Writing Clearly in Academic Papers
• Title-page generator
• APA style hub
• MLA style hub
• Chicago style hub