Google AI Max Migration Is Live: What Actually Changed in Your Search Campaigns on September 1?

September 1 was not a soft deadline. Google began automatically migrating Search campaigns using Campaign-level Broad Match and legacy Automatically Created Assets to AI Max, with no opt-out available. Here is what actually changed and what to do right now.

If your Google Ads account included campaigns using Campaign-level Broad Match settings or standalone Automatically Created Assets (ACA), those campaigns are now being upgraded to AI Max whether you prepared for it or not. The migration is rolling out gradually through September, meaning some campaigns in your account may have already changed while others are still in queue.

The most useful thing you can do right now is not panic, but also not ignore it. The September 1 migration is real, the changes to how your campaigns function are significant, and the performance trajectory over the next four to six weeks needs to be watched closely with a clear framework for what counts as expected turbulence versus genuine deterioration.

What Happened on September 1

Starting September 1, 2026, Google began automatic in-place migration of any Search campaign that was still using the Campaign-level Broad Match setting or had legacy Automatically Created Assets enabled. These campaigns are being converted to AI Max with settings that Google describes as “equivalent” to the previous configuration. Brand inclusions and exclusions that were set on the original campaigns are carrying over automatically.

Note what is not included in this migration: Dynamic Search Ads. After significant advertiser pushback reported by Search Engine Land and other sources, Google moved the DSA-to-AI-Max migration to February 2027. Only Campaign-level Broad Match and ACA campaigns are in scope for the September 2026 wave. If you were running standard keyword-targeted Search campaigns, nothing changes for those until future announcements.

Google stopped allowing creation of new Campaign-level Broad Match and legacy ACA campaigns in Ads Manager, Ads Editor, and via API from August 3, so if you were planning to create new campaigns in those formats, that option no longer exists regardless of migration timing.

Which Campaigns Were Affected

To check which of your campaigns were in scope, go to your Campaign list in Google Ads and look for any campaigns tagged with AI Max in the campaign type or status column. You can also check the Recommendations tab, which should flag any campaigns that were migrated or are pending migration in your account.

Campaigns using standard keyword targeting with exact match, phrase match, or regular broad match at the keyword level, without the campaign-level broad match overlay, are not in the September 1 migration scope. Performance Max campaigns are a separate product entirely and were not affected by this wave. If you are uncertain whether a specific campaign was in scope, check the campaign’s change history in Google Ads, which will log the migration event if it occurred.

What AI Max Actually Does

AI Max for Search is a campaign setting, not a separate campaign type. It enables three capabilities that were not available in Campaign-level Broad Match or ACA: AI-powered keyword expansion that serves ads on semantically relevant queries beyond your keyword list, AI-generated text asset creation that produces new ad headlines and descriptions from your landing pages and existing assets, and broader URL expansion that can direct traffic to the most relevant page on your site rather than always using the final URL from your ad.

These capabilities give Google significantly more control over where your ads appear and what they say. The keyword expansion means your ads can surface on queries that were not in your original keyword list. The text asset generation means Google may use ad copy it generated rather than copy you wrote. The URL expansion means clicks may land on pages other than the one you specified in the ad, as long as they are on the same domain.

Each of these features can be configured. URL expansion can be restricted or disabled. Text asset generation can be turned off if you prefer your manually written copy. Keyword expansion can be monitored through the Search Terms report. Understanding which of these settings are active in your migrated campaigns is the first step before drawing conclusions about performance changes.

The Performance Gap

The performance data on AI Max migration is genuinely mixed, and the gap between Google’s claims and independent measurement is worth knowing before you evaluate your own results.

Google’s own reporting cites an average 7 percent improvement in conversions across campaigns migrated to AI Max. Independent testing tells a different story: analysis across more than 250 retail campaigns by digital marketing researchers recorded a 35 percent ROAS decline in the first four weeks post-migration, according to data reported by Improvado and reviewed by Search Engine Land. The divergence is large enough to suggest that performance outcomes depend heavily on account structure, industry, and how well the existing campaigns were optimised before migration.

The most likely explanations for the ROAS gap in negatively affected accounts include: AI Max keyword expansion serving ads on lower-intent queries that the legacy campaigns were not reaching, AI-generated text assets that perform below the quality of carefully written manual copy, and URL expansion directing traffic to pages with lower conversion rates than the advertiser-specified landing page. Each of these is diagnosable and adjustable if you monitor your Search Terms report, asset performance data, and landing page analytics carefully in the weeks following migration.

What to Monitor Now

For any campaign that migrated to AI Max, pull your Search Terms report for the two weeks before and two weeks after the migration date. Look for query types appearing post-migration that were not present before, particularly informational queries, very broad brand-adjacent queries, or competitor brand terms that the keyword expansion is now matching. Add any query types that are clearly low-intent as negative keywords.

Check your Asset Performance report for any AI-generated headlines or descriptions that are flagged as “Learning” or “Low” performance. If AI-generated assets are underperforming your manually written ones, you can pin your best manual assets to specific positions to limit how often AI-generated copy is used.

Monitor your landing page distribution in the URL report. If URL expansion is active and sending traffic to pages other than your intended landing pages, assess whether those pages have comparable conversion rates. If they do not, restrict URL expansion to your specified URLs or tighten the domain pages that are eligible.

At Incisive Growth, our Google Ads management team is reviewing migrated campaigns weekly through September to identify and address any of these post-migration performance patterns before they compound.

Common Mistakes to Avoid

Making Drastic Changes Immediately

AI Max campaigns need time to accumulate learning signal before their performance stabilises. Making large budget cuts, bid changes, or structural changes within the first two weeks of migration resets the learning phase and makes performance evaluation impossible. Observe for at least two to three weeks before making structural decisions, unless you see clear signs of spend being wasted on genuinely irrelevant queries.

Assuming All Post-Migration Performance Changes Are AI Max

September always brings some natural performance variation as Q4 preparation changes competitive pressure, bid landscape, and user behaviour. Not every performance change you see in September is attributable to the migration. Compare migrated campaigns against non-migrated campaigns in the same account and against year-over-year benchmarks before attributing changes to AI Max specifically.

Ignoring Negative Keyword Management

AI Max keyword expansion will surface your ads on query types that your previous campaigns did not serve. Some of those queries will be valuable. Some will not. The most common post-migration waste comes from expanded queries with very low commercial intent. Review the Search Terms report weekly and add negatives aggressively in the first month of AI Max operation.

What This Means Going Forward

The September AI Max migration is phase one of Google’s broader push to move all Search campaign traffic through AI-powered delivery by early 2027. The DSA migration to AI Max follows in February 2027. The direction is clear: Google is centralising all Search campaign delivery through AI Max over the next eighteen months.

This means the time to get comfortable operating within AI Max is now, not after the February wave. Understanding how to configure AI Max features, monitor its performance signals, and use the available controls to guide its behaviour is becoming a core skill for anyone managing Google Ads accounts. The advertisers who build that fluency through the September migration will be better positioned for the February DSA migration and for whatever comes next.

At Incisive Growth, we manage Google Ads accounts through migrations like this with a structured monitoring framework that identifies post-migration issues early and implements the right configuration adjustments before performance deteriorates materially. If your account went through the September migration and you are not sure what changed or what to watch, reach out for a post-migration audit.

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