Google is not asking this time. Starting in September 2026, Search campaigns running automatically created assets or campaign-level broad match get moved to AI Max whether or not anyone logs in to click confirm. Dynamic Search Ads campaigns get a longer runway, now pushed to February 2027 after advertiser pushback, but the direction has not changed. If your account has not been audited for this, the migration will happen anyway, quietly, and you will find out from your CPA report a few weeks later.
In September 2026, Google auto-upgrades Search campaigns using automatically created assets or campaign-level broad match to AI Max. Dynamic Search Ads campaigns migrate separately in February 2027. Google reports about 7% more conversions at similar CPA when the full AI Max feature set is used together, but accounts with weak exclusions typically see the opposite. Audit negatives and URL exclusions before it happens, not after.
What is actually changing in September?
AI Max for Search is Google's expanded automation layer on top of standard Search campaigns: it broadens keyword matching using search term matching, generates and tests ad text automatically, and can send traffic to different landing pages on your domain than the one you set, through final URL expansion. It has existed as an opt-in feature. What changes in September is that it stops being opt-in for a specific set of campaigns.
Three campaign types are affected. Campaigns using Dynamic Search Ads, campaigns using automatically created assets (ACA), and campaigns with campaign-level broad match set are all being folded into AI Max. Google originally targeted DSA migrations for the same September window as the other two, then revised the DSA timeline specifically to February 2027, citing advertiser feedback and the timing conflict with Q4 retail season. ACA and broad match campaigns keep the original September date. If you are not sure which category your accounts fall into, that is the first thing to check, because the two timelines require different urgency.
Why this keeps happening: the pattern behind AI Max
This is not an isolated change. Google has spent 2026 pushing more of the ad account toward automated decision-making by default, not by request, a trend that shows up across Performance Max expansion, automatically applied recommendations, and now this migration. The pitch is consistent: better outcomes with less manual tuning, in exchange for less visibility into exactly which query triggered which impression.
| What's migrating | New auto-upgrade date | What it does |
|---|---|---|
| Automatically created assets (ACA) campaigns | September 2026 | Folded into AI Max, gains automated text and search term matching |
| Campaign-level broad match campaigns | September 2026 | Folded into AI Max, matching broadens further under automation |
| Dynamic Search Ads (DSA) campaigns | February 2027 (delayed from September 2026) | Folded into AI Max, DSA-specific ad group structure retired |
Google states that AI Max delivers roughly 7% more conversions or conversion value at a similar cost per acquisition or ROAS, but only when advertisers use the complete feature set: search term matching, text customization and final URL expansion running together rather than a subset. That is the number worth remembering, because it is a best case built on full adoption, not a guarantee for an account that gets migrated with default settings and no review.
We are treating this the same way we treated the last few Performance Max expansions: assume the migration happens whether the account owner is ready or not, and get the guardrails in place beforehand rather than reacting to a CPA spike afterward. That means reviewing negative keyword lists for gaps that broader matching will expose, and confirming URL exclusions are actually set on any page that should never receive expanded search traffic, like a checkout page, a careers page, or a page for a discontinued product line.
What should you check before your account gets migrated?
- Pull a search terms report for the last 90 days on any campaign using ACA or broad match, and look specifically for irrelevant queries that already slipped through. If they are already there, expanded matching will make them worse, not better.
- Set explicit URL exclusions for any page final URL expansion should never touch: checkout, account, careers, discontinued products, and any page with outdated pricing.
- Review negative keyword lists at the account and campaign level. Thin negative lists are the single biggest predictor of CPA drift after an automated matching expansion.
- Confirm conversion tracking is accurate and deduplicated before the migration, since a migration is the worst possible time to discover your conversion count was already wrong.
- Set a calendar reminder to check performance seven and fourteen days after the auto-upgrade lands, not thirty, so a bad pattern gets caught while it is still cheap to fix.
Does this affect Performance Max too?
Not directly. This particular auto-upgrade is scoped to Search campaigns running ACA, broad match, or DSA. Performance Max is a separate campaign type with its own automation model, and it is not part of this migration. It is worth naming as the same underlying pattern, though: Google is consistently narrowing the gap between what you configure and what the system decides on your behalf, one campaign type at a time. Treat AI Max the way you should already treat Performance Max, which is with active guardrails rather than passive trust.
What does this mean for your CAC and reporting?
Two practical risks show up after migrations like this. First, blended CAC can shift even when platform-reported ROAS looks stable, because expanded matching pulls in traffic your existing attribution model was not built to categorize cleanly. If you track blended ROAS separately from platform-reported ROAS, watch the gap between them widen or narrow in the weeks after the migration, since that gap is often the first honest signal something changed. Second, budget pacing can shift as the system tests new query and asset combinations, which can look like a spend spike if you are not expecting it.
For clients on retainer, we are running the pre-migration audit above during August rather than waiting for the September rollout, specifically for any account running ACA or campaign-level broad match. It is a few hours of work against a search terms report and exclusion list, and it is considerably cheaper than discovering a CPA problem three weeks into Q4 planning.
Frequently asked questions
What is Google auto-upgrading to AI Max in September 2026?
Starting in September 2026, Google is automatically upgrading Search campaigns that use automatically created assets (ACA) or campaign-level broad match to AI Max for Search. Campaigns built specifically on Dynamic Search Ads follow a separate, later timeline pushed to February 2027 after advertiser feedback.
Do I have to accept the AI Max upgrade?
Google is applying the upgrade automatically to eligible campaigns rather than asking first. You can adjust AI Max settings, including turning off search term matching or final URL expansion individually, after the migration completes, but you cannot opt an eligible campaign out of moving to the new campaign type entirely.
Will my cost per acquisition change after the AI Max migration?
Google reports AI Max delivering about 7 percent more conversions or conversion value at a similar CPA or ROAS when advertisers use the full feature set together: search term matching, text customization and final URL expansion. Results vary by account, and accounts with weak URL exclusions or thin negative keyword lists are the ones most likely to see CPA drift upward instead.
What should I check before my account gets auto-upgraded?
Audit your negative keyword lists, set brand and URL exclusions explicitly rather than relying on defaults, review any landing pages that should never receive expanded traffic, and confirm your conversion tracking is accurate before the migration. Fixing these after the fact means paying for the mistakes AI Max makes while it is still learning your account.
Does this affect Performance Max campaigns too?
No, this specific migration applies to Search campaigns using automatically created assets or campaign-level broad match, and separately to Dynamic Search Ads campaigns on their own later timeline. Performance Max is a distinct campaign type and is not part of this particular auto-upgrade, though it follows the same broader trend of Google shifting budget control toward automated systems.
The takeaway
The September AI Max migration is not optional and is not far off. The accounts that come out ahead will be the ones that treat it as a scheduled audit rather than a surprise: clean negative lists, explicit URL exclusions, verified tracking, and a plan to check performance within two weeks of the change rather than waiting for the monthly report to catch it. Everyone else will be explaining a CPA jump to a client or a boss without a clear story for why it happened.