In running text, "artificial intelligence" is a common noun and stays lowercase, while the abbreviation "AI" is always written in capitals. The full phrase takes capitals only when it opens a sentence or sits inside a proper name, such as the Pan-Canadian Artificial Intelligence Strategy or the National Artificial Intelligence Initiative Act of 2020. Government style guidance and federal publications in Canada and the United States follow this pattern.
Key takeaways
- United States federal law defines the term in lowercase inside quotation marks, in 15 U.S.C. 9401.
- Program, strategy, and statute titles capitalize their main words, and the short form ("the strategy") goes back to lowercase.
- The Government of Canada style guide and NIST both spell out the term once with "(AI)" after it and then use "AI" alone.
- Title-case headings capitalize each main word, while sentence-case headings capitalize only the first word.
- Commercial style manuals differ on details, so a publication's own house style settles the open cases.
The default: lowercase for the idea, capitals for the abbreviation
The Government of Canada's Content Style Guide sets the general principle in section 4.1: capitalize the main words of program names, titles of policy instruments, and titles of legislation, and lowercase the short form of a proper name. It adds that all capitals are generally reserved for abbreviations and military operation names. Applied to this topic, the phrase "artificial intelligence" names a field of technology rather than a specific institution, so nothing in the guide calls for capitals. The two letters "AI" are an abbreviation, so they are written in capitals wherever they appear in a sentence, and the sources reviewed here write them without periods.
The same reasoning explains why "machine-made" or "AI-driven" phrasing never needs extra capitals inside a sentence. A capital letter signals a name, and a general description of a technology is not a name.
What federal law and agency documents show
Law and agency writing give the most checkable examples. In the United States, 15 U.S.C. 9401, which sits in the code under the National Artificial Intelligence Initiative Act of 2020, defines the term as follows: the term "artificial intelligence" means a machine-based system that can, for a given set of human-defined objectives, make predictions, recommendations or decisions influencing real or virtual environments. The defined term is lowercase inside the quotation marks, while the short title of the Act is in title case because it is a name.
The National Institute of Standards and Technology (NIST) writes on its AI Risk Management Framework page that it developed a framework for risks tied to "artificial intelligence (AI)," spelled out once and then shortened to "AI." The framework's title, Artificial Intelligence Risk Management Framework (AI RMF 1.0), released on January 26, 2023, is capitalized because it is the title of a document. A later companion, NIST AI 600-1, published on July 26, 2024, is titled Artificial Intelligence Risk Management Framework: Generative Artificial Intelligence Profile, again in title case.
Canada shows both forms side by side. CIFAR, which describes the program on its site, gives its official name as the Pan-Canadian Artificial Intelligence Strategy and says it launched in 2017, while the heading on the same page shortens it to "The Pan-Canadian AI Strategy."
When capitals are correct
The table sorts common situations by what the words refer to. It summarizes the sources above and is a simplified guide rather than a complete rulebook.
| Situation | Form | Example | Basis |
|---|---|---|---|
| General concept in a sentence | Lowercase | Banks are adding artificial intelligence to fraud screening. | Defined term in 15 U.S.C. 9401 is lowercase |
| Abbreviation | AI, all capitals | The agency published an AI inventory. | Government of Canada guide: all capitals reserved for abbreviations |
| Start of a sentence | Capital first letter | Artificial intelligence is the subject of the report. | Ordinary sentence rule |
| Title of a statute | Capitalize main words | National Artificial Intelligence Initiative Act of 2020 | Government of Canada guide: titles of legislation; the statute's own short title |
| Program or strategy name | Capitalize main words | Pan-Canadian Artificial Intelligence Strategy | Government of Canada guide: program names; CIFAR |
| Short form of that name | Lowercase | The strategy funded three institutes. | Government of Canada guide: lowercase the short form |
| Title of a publication | Capitalize main words | Artificial Intelligence Risk Management Framework | NIST publication titles |
One case the table leaves out is the field of study. The sources reviewed treat the phrase as a common noun even when it names a discipline, in the same way that physics or economics is not capitalized in the middle of a sentence.
First mention, the abbreviation, and short forms
Section 4.4 of the Government of Canada guide tells writers to give the long form with the abbreviation in parentheses at first mention, and to use the abbreviation alone afterward. It also advises avoiding abbreviations where possible. NIST's page follows the same sequence. For a short article, that means writing "artificial intelligence (AI)" once and "AI" thereafter. For a page where many readers arrive at a lower section from a search result, repeating the full phrase near the first use in that section is a reasonable extra step, and nothing in the guide forbids it.
The short-form rule matters for program names. After the first full mention of the Pan-Canadian Artificial Intelligence Strategy, later references such as "the strategy" or "the program" take no capitals, because the Government of Canada guide asks for lowercase short forms of proper names.
Headings, titles, and sentence case
Heading style changes the picture without changing the rule. The Government of Canada guide asks for sentence case in headings: capitalize the first word and proper nouns, and add no punctuation at the end. A heading such as "Artificial intelligence in public services" follows that rule. NIST publication titles use title case, so each main word carries a capital. Neither style claims that "artificial intelligence" is a proper noun; the capitals come from the heading convention. A site or publication should choose one heading style and keep it throughout.
A four-question check before publishing
- Is the phrase part of an official name, such as a law, program, strategy, or document title? If so, copy the capitalization from the official source.
- Is it the abbreviation? Write "AI" in capitals, and spell out the term at first mention.
- Does it begin a sentence or a title-case heading? Capitalize by that rule alone.
- Is it a later reference to a named program? Use a lowercase short form.
FAQ
Should "artificial intelligence" be capitalized in the middle of a sentence?
No, not as a general term. Federal law in the United States defines it in lowercase, and Canadian government guidance reserves capitals for proper names, titles, and abbreviations.
Is "AI" always capitalized?
Yes. It is an abbreviation, and the Government of Canada guide limits all-capital words to abbreviations and military operation names. The government sources reviewed write it without periods.
How should "generative AI" be written?
In a sentence, "generative AI" is lowercase except for the capitals in "AI." A document title such as NIST's Generative Artificial Intelligence Profile is capitalized because it is a title.
Does a heading change the answer?
Only through the heading style. Sentence-case headings capitalize the first word, and title-case headings capitalize each main word. The phrase itself is still a common noun.
Which style manual decides the question?
The publication's own house style. Commercial manuals sold by subscription were not consulted for this article, so the guidance here rests on government sources.
Related reading
- Whether AI requires coding
- Whether AI counts as a computer
- How AI learns from new information
- The role of mathematics in AI
More in AI Basics.
Last verified: October 2026
Sources
- Content Style Guide, sections 4.1 and 4.4, Government of Canada web design system, Government of Canada, 2026
- 15 U.S.C. 9401, definitions under the National Artificial Intelligence Initiative Act of 2020, United States Code
- AI Risk Management Framework, National Institute of Standards and Technology, released January 26, 2023
- Artificial Intelligence Risk Management Framework: Generative Artificial Intelligence Profile (NIST AI 600-1), NIST, July 26, 2024
- The Pan-Canadian AI Strategy, CIFAR, 2026