On 1 September 2026 Google begins automatically upgrading Search campaigns that run campaign-level broad match or standalone automatically created assets to AI Max, and there is no opt-out once the rollout reaches your account. The migration runs progressively across the whole of September rather than flipping every campaign at once, which means a campaign untouched on 2 September might still shift on 24 September. Search Engine Land confirmed the September 1–30 timeline with no opt-out after the deadline, and creation of new campaign-level broad match and legacy ACA setups already stopped on 3 August 2026.
For anyone who manages wasted spend, the important part is not the branding change — it is that a migrated campaign arrives with a wider matching surface than the one you built your negative list against. Your negatives still apply, but they were written for the queries your old keywords reached, and AI Max is designed to reach past them. This is a checklist for the roughly ten days before the deadline: what to audit in your search terms report and negative lists so the upgrade lands on a clean account instead of an unmonitored one. It is the migration-prep companion to the mechanics covered in when AI Max overrides your negative keywords.
Get the deadline right before you plan around it
The single most useful thing you can do first is separate this September event from the DSA timeline that shares its headlines. What happens on 1 September 2026 is the auto-upgrade of campaign-level broad match and automatically created assets to AI Max, rolling out through the month. Dynamic Search Ads are on a later, separate track and do not fully migrate until February 2027. If you have been treating "the September deadline" as a single DSA cliff, you are planning around the wrong date and may audit the wrong campaigns.
Confirm which of your campaigns are actually in scope. Open each Search campaign and check whether it uses campaign-level broad match settings or standalone automatically created assets — those are the ones the auto-upgrade targets. Campaigns already structured around keyword-level match types without ACA are not the subject of this particular flip, though the broader direction of travel still points at AI Max. Knowing exactly which campaigns will move, and roughly in what window, tells you where to concentrate the audit time you have before the first of the month.
Export a search terms baseline now
Before any campaign migrates, export its current search terms report and save it as a dated baseline. Once AI Max expansion turns on, you will want to compare the post-migration query mix against the pre-migration one to see exactly what expansion added — and you cannot do that comparison if you never captured the "before" state. Pull at least the last 30 days, sorted by cost, and keep the columns that matter for waste: query, match type, cost, clicks, conversions, and conversion value.
This baseline also does double duty as a negative-mining pass. Any high-cost, zero-conversion theme sitting in the report today is waste you should block regardless of the migration, and blocking it now means it is already excluded when the wider surface arrives. Work the report the way the search terms report walkthrough describes: judge themes by spend and conversions rather than by how the wording reads, and negate the concept rather than a single string. A clean baseline is both your comparison point and a head start on the negative coverage the migrated campaign will need.
Move containment to campaign and account-level lists
In a classic broad-match campaign, tight ad-group structure did much of the containment work. AI Max breaks that model deliberately, so the lever that survives the migration is the campaign-level or account-level negative list, which applies across expanded queries the same way it applies to your keywords. Before your campaigns flip, confirm your shared negative lists are actually attached at the campaign level rather than living in ad-group exclusions that expansion will route around.
Then broaden those lists to match a wider surface. Build robust thematic blocks — the job and salary words, the free and DIY words, the wrong-product and wrong-geography words, the competitor and research-intent queries that never convert for you — and apply them at the campaign level so they cover expansion, not just your literal keywords. A thin list that was survivable under tight structure becomes expensive when expansion is doing the matching. This is the same discipline the hidden wasted-spend audit already teaches; the migration just raises the stakes on getting the lists complete before the surface widens.
Verify conversion tracking and cap the downside
AI Max leans on Smart Bidding, and Smart Bidding is only as good as the conversion signal you feed it, so verify your tracking before the migration rather than after. Confirm that conversions are firing on the right actions, that you are not double-counting, and that any recent tag changes actually record. A campaign that migrates to AI Max with a broken or noisy conversion signal will let the system optimise toward the wrong queries, and the search terms report will fill with expansion you then have to unwind.
Give yourself a financial guardrail for the first weeks too. The learning period is when expansion reaches its widest and least-filtered, so treat the immediate post-migration window as higher-risk on spend. Keep budgets where a bad week cannot do outsized damage, and plan to review daily rather than trusting the campaign to settle on its own. The goal is not to fear the upgrade but to bound the downside while you learn what expansion is actually matching in your account.
Run a daily search-terms pass through the flip
Once a campaign migrates, check its search terms report every day for the first week. This is when expansion surfaces the most unfamiliar queries, and catching irrelevant themes early stops them compounding into a month of drift. Feed the waste into campaign-level negatives as you find it, and compare the live query mix against the baseline you exported so you can see precisely what the migration added. After the two-to-four-week learning period, drop to a weekly thematic pass and fold it back into your normal cadence.
Read the report against outcomes, not just wording — a caution that matters more now that Google may show an AI-interpreted version of the query on some surfaces rather than the literal text. Keep the written log every good negative workflow uses: the term, the level, the date, and why. AI Max expansion plus interpreted reporting makes after-the-fact reconstruction hard, and a campaign-level negative that reaches too far can quietly cut volume across the whole campaign. The account that comes through the September migration in good shape is the one that walked in with a baseline, complete campaign-level lists, clean tracking, and a daily report habit — not the one that found out what AI Max matched from the invoice.