How Google chooses the sources in an AI Overview

01How does Google choose the sources in an AI Overview?

Google does not keep a separate list of approved AI sources. A page must already be indexed and eligible to show a normal snippet in Google Search, meeting the same Search technical requirements as any other result¹. From that eligible pool, Google's systems use a technique called query fan-out, running several related searches behind the scenes, to surface more supporting pages than a classic search result page would show¹. Google says its generative AI features are rooted in the same core Search ranking and quality systems used for ordinary results², and that there are no additional requirements or special optimizations needed to appear in AI Overviews or AI Mode¹.

02What actually makes a page eligible?

Eligibility for an AI Overview is the same eligibility Google already uses for a normal blue link with a snippet: the page has to be indexed, crawlable, and compliant with Search's policies¹. Google is explicit that no extra files or markup are needed, including the kind of llms.txt files some vendors now sell to health practices².

• Allow Googlebot to crawl your pages in robots.txt¹
• Keep the real answer in plain text on the page, not locked inside an image, PDF, or embedded video¹
• Link your service and location pages to each other so Google can find them through your own site¹
• Keep your Google Business Profile and any product feeds current¹

Page experience is on that same list of best practices¹; our guide to site speed for practice websites covers what that means in plain terms. Google announced a new Search Console control in June 2026, updated in August 2026, that lets a site owner choose whether to appear in generative AI features such as AI Overviews, AI Mode, and AI Overviews in Discover³. Google's own guidance confirms a site must be included in that generative AI features setting in Search Console to be eligible for display in these features². Google says this rolled out to all websites worldwide by the end of August 2026³, so it is worth checking that setting rather than assuming your site is automatically included.

03What is query fan-out, and why does it widen the pool of sources?

Google describes retrieval-augmented generation, or RAG, as the technique behind AI Overviews: the system relies on Google's core Search ranking to retrieve relevant, up-to-date pages from the index, then reviews the specific information on those pages to write a response with clickable links². Query fan-out is the step that expands the search. Google calls it "a set of concurrent, related queries generated by the model to request more information and fetch additional relevant search results"². In practice, this means a single, well-answered page about, say, what to expect at a first visit can surface for several differently worded patient questions, not only the exact phrase written on the page¹. Google also reports that clicks arriving from a results page with an AI Overview tend to be higher quality, meaning visitors spend more time on the site once they arrive¹.

04Can a practice opt out, or pay to get in?

A site owner can now opt out of generative AI features entirely through the Search Console setting. Google says sites that opt out "will not receive traffic or impressions from our generative AI features," and that the setting "will not be used as a ranking signal for search results outside of these generative AI Search features"³. That is useful to know: opting out removes a practice from AI Overviews and AI Mode without, according to Google, changing how the site ranks in ordinary search results.

Advertising works differently. Google Ads can run above, below, or inside an AI Overview⁴, but currently "we don't show ads in AI Overviews for sensitive verticals like adult, alcohol, gambling, finance, healthcare, politics, and more"⁴, and advertisers cannot choose to target only AI Overview placements⁴. For a health or wellness practice, that means there is no ad budget that buys a spot inside the Overview's written answer.

05How do you check whether your practice is showing up?

AI Overview clicks are folded into the regular Search Console Performance report, under the "Web" search type, alongside the rest of your search traffic¹. Google also offers a separate Generative AI performance report in Search Console showing impressions for pages appearing specifically in generative AI features². Before treating either report as a verdict on quality, remember Google's own warning: "AI Overviews can and will make mistakes," and Google recommends checking important information in more than one place⁵. If an AI Overview cites your practice, that confirms your page was found and used as a supporting link, not that every detail in the summary is accurate.

06What counts toward eligibility, and what doesn't?

07What should a practice do this month?

• Confirm your site is verified in Search Console and check the generative AI features setting rather than assuming it is on³.
• Test your robots.txt file to make sure Googlebot can reach your key service and location pages¹.
• Put the plain-text answer to common patient questions directly on the page itself, the way service pages patients can actually read are written, not only inside a photo or video.
• Check the Performance report's Web search type and the Generative AI performance report monthly for changes in impressions¹².
• If you want an outside look at how your site reads to Google and AI systems, run a free credibility check.

None of this guarantees a citation. Google says plainly that meeting requirements and best practices does not mean a page will be crawled, indexed, or served¹. Start with the robots.txt check and the Search Console setting together, since either one alone can quietly keep an otherwise good page out of AI Overviews.