If your Google Search campaigns still use Broad Match with Auto-Created Assets, Google is changing them this month whether you ask it to or not. From 1 September through 30 September 2026, Google is automatically migrating any remaining campaigns on those legacy settings into AI Max, its newer AI-driven search-campaign format.
This isn't a new option appearing in your account for you to consider. It's an automatic conversion running on a fixed schedule right now, and if you haven't checked your account this month, campaigns may already have changed underneath you.
How we got here
Google blocked the creation of new Search campaigns using legacy Broad Match and Auto-Created Assets settings starting 3 August 2026. That closed off new campaigns from using the old setup, but it left existing campaigns on those settings untouched, for the time being. That grace period ends this month.
Between 1 and 30 September 2026, Google is running the migration itself, moving existing campaigns still configured with Broad Match and Auto-Created Assets over to AI Max. AI Max is Google's newer format for search campaigns, built around its AI systems handling more of the targeting, creative assembly and matching decisions than the advertiser configures manually.
What actually changes for you
The mechanics matter here. Broad Match and Auto-Created Assets and AI Max are not equivalent settings with a different name, they're different systems for how your ads get shown and to whom. A campaign that has been tuned over months to perform a certain way under the old settings will behave differently once Google's AI systems are making more of those decisions, and that can show up as a shift in impressions, click-through rate, cost per click, or conversion volume, in either direction.
Because this is an automatic, account-wide migration rather than something you request, the shift can land without any change log entry pointing you to the cause. If your numbers move this month, the natural instinct is to look at what your team changed. This time, the answer might be that you didn't change anything, Google did.
What to actually do
Go into your Google Ads account this week and check every active Search campaign for its match type and asset settings. Anything still running on Broad Match with Auto-Created Assets is a candidate for this migration, or may already have been converted if it happened earlier in September.
Look at the campaign-level change history in Google Ads for each of those campaigns to see whether the migration has already run. If it has, note the exact date, since that's your marker for before-and-after comparisons in performance reporting.
Pull performance data for the two weeks before and, once available, the two weeks after the migration date for each affected campaign. Compare cost per click, conversion rate and overall spend rather than just top-line clicks, since AI Max campaigns can shift where and how often your ads show in ways that don't move every metric the same direction.
If a migrated campaign's performance drops in a way that matters to your budget, don't assume you're stuck with AI Max forever. Talk to your Google Ads rep or check the campaign settings for whether a rollback or a rebuild under manual settings is available, and treat that as a live decision for this quarter rather than something to revisit at renewal time.
Brief anyone else on your team who touches paid search, including an agency or freelancer, that this migration is happening account-wide in September regardless of what anyone requests. If someone reports a strange shift in campaign behaviour this month, this migration should be the first thing checked, not the last.
Why the timing is worth noting
The two dates matter more than they might first appear. Blocking new campaigns from using Broad Match and Auto-Created Assets from 3 August 2026 gave Google roughly a month's notice before it started touching existing campaigns. If you missed that first change, or didn't connect it to what's happening now, this is the follow-through: the full month of September is the active migration window for anything left on the old settings, not a soft deadline that slips.
That also means the window to catch a campaign before it changes is closing as September runs out. If you're reading this partway through the month and haven't checked your account yet, treat it as urgent rather than something to schedule for next sprint. A campaign migrated on 5 September has already had over a week to run under AI Max before you'd even notice, if you weren't watching for it.
It's also worth checking whether your account has any campaigns paused or low-spend enough that you haven't looked at them in months. Google's migration doesn't appear to distinguish between an actively managed campaign and a dormant one still sitting on legacy settings. A quiet, low-priority campaign is just as likely to be swept into this change as your top performer, and it's easy to overlook precisely because nobody's been checking it regularly.
The bottom line
Google is automatically converting Search campaigns still on Broad Match and Auto-Created Assets into AI Max throughout September 2026, with no opt-in required from advertisers. Check your account for legacy campaigns now, note the exact migration date wherever it applies, and watch performance closely this month rather than assuming any shift in your numbers came from something your own team did.