AI Max Migration Checklist Before Sept 30
An AI Max migration checklist is worth running this week, not next quarter, because the window to catch what changed closes September 30, 2026. Google blocked new campaign-level Broad Match and legacy Automatically Created Assets setups back on August 3, then spent September auto-migrating every eligible Search campaign still running the old setup, flipping search term matching and text customization on by default whether or not an advertiser asked for either. Google's own [Ads & Commerce blog](https://blog.google/products/ads-commerce/dsa-upgrade-to-ai-max-2026) frames the migration as settings carried over in place, and independent coverage from [Search Engine Land](https://searchengineland.com/google-sets-ai-max-migration-timeline-for-search-campaigns-485006) and [ppc.land](https://ppc.land/google-blocks-new-broad-match-settings-before-september-1-ai-max-migration/) confirms brand exclusion lists do move over intact. What does not survive the migration untouched is campaign behavior, new defaults change what the campaign actually does with your budget starting the day it migrates, no matter what Google preserved on paper.
What actually auto-migrated between September 1 and 30
Two cohorts moved automatically this month: Search campaigns still running campaign-level Broad Match, and standalone Automatically Created Assets (ACA) campaigns that had not been folded into a newer setup. Google closed the door on new legacy setups first, on August 3, 2026 creating a new campaign-level Broad Match configuration or a new legacy ACA campaign was blocked across the Google Ads UI, Ads Editor, and every version of the API, confirmed by TechWyse's coverage of the rollout. From September 1 through September 30, Google auto-migrated every remaining eligible campaign in place, same campaign ID, same budget, same bids, same ad copy, just running under AI Max's matching and asset logic instead of the legacy setup. If a campaign in your account was still on campaign-level Broad Match or legacy ACA on September 1, it has migrated or is migrating before the month closes, whether or not anyone on the account opted in.
| Setting | Broad Match cohort | ACA cohort |
|---|---|---|
| Search term matching | On by default | On by default |
| Text customization | Off by default | On by default |
| Final URL expansion | Off by default | Off by default |
| Campaign ID | Unchanged | Unchanged |
| Brand inclusion/exclusion lists | Carried over in place | Carried over in place |
What "carried over" means, and what it does not
Google's messaging on this migration is specific: brand inclusion and exclusion lists move into the new AI Max configuration automatically, and the campaign is migrated in place using equivalent settings, not rebuilt from scratch. That is true, and worth confirming rather than assuming, brand lists do transfer. What that language does not cover is behavior. Search term matching on a Broad Match cohort campaign was previously your keyword list; after migration it is your keyword list plus an intent layer deciding which additional queries also qualify, turned on by default the moment the campaign migrates. An ACA cohort campaign now has text customization on by default too, meaning Google is actively rewriting ad copy variations in that campaign unless someone turns it off. Nothing about brand lists carrying over intact tells you whether the intent layer or the copy rewriting is doing what your account needs, that is a separate, unrelated question the "carried over" framing does not answer.
Preserved and unchanged are not the same claim. Google preserving your brand exclusion list is real and verifiable. Google preserving your campaign's actual behavior at the same time it flips two new defaults on is a different claim entirely, and it is the one worth auditing before September 30, not after.
Find your exact migration timestamp with the new reporting fields
Google shipped two new fields specifically for this rollout: campaign.aca_migration_date_time and campaign.broad_match_migration_date_time, available through the Google Ads API and reporting tools, confirmed in TechWyse's writeup of the migration. Pull whichever field applies to a given campaign and you get the exact timestamp it flipped over, not the month it happened in. That timestamp is the only reliable anchor for a clean before/after comparison, a month-over-month view blends pre- and post-migration days into one average and hides the actual delta the new defaults caused.
Audit checklist before the September 30 close-out
| Check | Why it matters |
|---|---|
| Pull campaign.aca_migration_date_time or campaign.broad_match_migration_date_time for each eligible campaign | Gives the exact hour a campaign switched over, the only clean anchor for a before/after performance comparison |
| Confirm brand inclusion and exclusion lists are actually present on the migrated campaign, not just assumed carried over | Google's own materials say lists transfer automatically, verify it in-account rather than take the claim on faith |
| Check whether text customization is on for any ACA cohort campaign where rewritten ad copy would be off-brand | ACA cohort campaigns get text customization on by default, Broad Match cohort campaigns do not |
| Review the search terms report for the days immediately after the campaign's migration timestamp | Search term matching is on by default for every migrated campaign, new query types can enter the auction the day it flips |
| If a campaign has not migrated yet, decide now whether to let it auto-migrate or disable Broad Match/ACA manually before it does | Manually disabling before migration is the only opt-out Google offers, and the window closes September 30 |
Who should own this before the window closes
Nobody in the account gets a banner the day a specific campaign's migration timestamp passes, the two new reporting fields have to be pulled deliberately to find it. Catching a platform-forced default change before a full quarter of spend runs under it is exactly what ongoing Paid Media and Analytics work exists for, someone checking the account against the actual migration timestamp, not the calendar month. It is the same pattern as Microsoft removing Max CPC bidding and the deeper audit this site already ran on AI Max's claimed lift versus measured account performance, platforms narrowing manual control and shipping the change with defaults turned on, leaving the burden of verification on the advertiser.
FREQUENTLY ASKED
What changed when my campaign auto-migrated to AI Max?
Search term matching turned on by default for every migrated campaign, and for Automatically Created Assets cohort campaigns, text customization turned on by default too. Brand inclusion and exclusion lists carried over automatically, and campaign IDs, budgets, and bids stayed the same.
Can I still opt out of the AI Max migration?
The only opt-out is manually disabling campaign-level Broad Match or legacy Automatically Created Assets before a specific campaign migrates. Creating a new legacy setup has been blocked since August 3, 2026, and the automatic migration window runs through September 30, 2026.
Did my campaign ID change during the AI Max migration?
No. Google migrates eligible campaigns in place, campaign IDs, budgets, bids, and ad copy stay the same, only the underlying matching and asset logic changes to AI Max's defaults.
How do I find exactly when a campaign migrated to AI Max?
Pull the campaign.aca_migration_date_time or campaign.broad_match_migration_date_time field for the campaign, whichever cohort it belongs to. That timestamp is the exact hour it switched over, and the only reliable anchor for a before/after performance comparison.
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