Google Ads Changed How Target-Based Bidding Works for Budget-Limited Campaigns

Starting August 17, 2026, Google changed how target-based bid strategies behave on any campaign marked "Limited by budget." If your Target CPA is set at $10 but your campaign has actually been delivering a $5 CPA because the budget cap was holding it back, that gap closes now, the campaign will start bidding more aggressively toward the full $10 target instead of quietly overperforming. It sounds like a technical footnote, but for accounts that have been relying on budget caps to keep CPA artificially low, this is a real shift in what your numbers will look like starting this week.

The Problem Google Says It's Fixing

Under the old system, a campaign flagged "Limited by budget" using Target CPA or Target ROAS could quietly overperform its stated target because the budget cap was the actual constraint, not the bid strategy. That sounds like a good problem to have, better-than-target CPA, but it meant your reported performance numbers didn't reflect what the campaign would actually do once you raised the budget: increase spend on a budget-limited campaign and performance would often degrade toward the real target rather than scaling proportionally, a frustrating surprise for anyone trying to plan growth off historical numbers. Google's fix makes budget-limited campaigns perform consistently toward the actual target you set, before you touch the budget, not after.

What This Means for Your Reported Numbers This Week

If any of your budget-limited Search, Shopping, Performance Max, Demand Gen, or Travel campaigns have historically delivered meaningfully better CPA or ROAS than the target you configured, expect that gap to close starting August 17. This isn't a sign your account got worse, it's the bidding system now matching your actual stated target instead of quietly beating it while budget held it back. The risk is a client or stakeholder seeing a CPA jump week over week and assuming something broke, when the real explanation is that Google changed what "hitting your target" means for budget-constrained campaigns.

What to Do Before Reporting This Month's Numbers

• Update your targets to match recent actual performance before the shift compounds. Google explicitly recommends this: if your real CPA has been $5 against a $10 target, tightening the target now keeps performance closer to what you were actually getting, rather than drifting toward the old, looser number.
• Use the new Bid Target Adjustment Tool rather than guessing at a new target manually. It's live in Google Ads now specifically to help recalibrate targets for this transition, and it's a faster, more accurate starting point than eyeballing historical CPA averages.
• Flag this proactively in any client or stakeholder report covering the August 17 window. A CPA or ROAS shift that traces back to a documented Google platform change is a very different conversation than one that looks like it came out of nowhere, get ahead of the question before it's asked.

A bidding mechanics change like this one is exactly the kind of update that's easy to miss until it shows up as an unexplained number in a monthly report, and by then you're explaining a mystery instead of a known platform change. If you manage budget-limited campaigns on Target CPA or Target ROAS, our Google Ads team can review your targets against recent performance now, before this shows up as a surprise in next month's numbers.