Google Is Changing How Target CPA and Target ROAS Work. Here’s What Happens on August 17

For years, a budget-limited campaign running Target CPA or Target ROAS could quietly outperform the number you set. A $50 Target CPA might deliver conversions at $35. Most advertisers treated that as a win and never touched it. Starting August 17, 2026, Google is closing that gap, and campaigns that have been overperforming will drift toward the target you originally entered, not the better number Smart Bidding has been delivering. This isn't a labelling tweak. It's a change to how the paid search bidding system behaves under budget constraints, and it can raise your real cost per conversion or reduce your ROAS overnight if you don't review your account first.

What's actually changing

Today, when a campaign using a target-based bid strategy is marked "Limited by budget," Google's bidding system has some flexibility to overperform its stated target. That flexibility is what lets a Target CPA of $50 quietly land at $35, or a Target ROAS of 400% land at 550%.

After August 17, that flexibility is removed for budget-limited campaigns. The system will optimize more consistently toward the exact target you've set, including when you raise or lower budgets. Google frames this as more predictable scaling: what you type is what you get, even after a budget change. The tradeoff is that any campaign currently benefiting from the old flexibility will see its performance shift back toward its target.

Note what doesn't change: Google will not automatically adjust your bidding targets or your budgets. If your current target of $50 no longer reflects what you're willing to pay, that's on you to fix before the 17th.

Why now and why brand campaigns are the biggest risk

Google's stated goal is predictability: budgets and targets should behave like two independent levers, not two settings that quietly interact. This is part of a broader push toward AI-driven campaign automation where what you type is increasingly what the system optimizes for, no hidden cushions. Under the old system, a budget change to a constrained campaign could cause unpredictable performance swings, because the system was managing both spend and an invisible efficiency cushion at the same time.

The accounts most exposed are the ones that have gotten comfortable with that cushion, brand campaigns in particular. Branded search terms convert at high rates and low costs almost by default, so a budget-limited brand campaign will often overachieve its target for months without anyone noticing. Those are exactly the campaigns that will feel the biggest jump in CPA, or the biggest drop in ROAS, when enforcement begins. For anyone reconsidering their branded search strategy in light of this, why you should run branded search ads even when you rank organically covers the case for keeping them running — and how to set them up to weather changes like this one.

Who's most exposed

Any campaign that has been "Limited by budget" at any point in the trailing 12 months, and is running Target CPA or Target ROAS. Google's lookback window is broad; a campaign that was budget-constrained for two weeks last fall and has run comfortably since can still be flagged.

Which campaigns are in scope
Search Shopping Performance Max Demand Gen Display Hotel Travel

This applies to Target CPA and Target ROAS across the campaign types above, and specifically to Target CPC for Demand Gen. Demand Gen campaigns managed in Display & Video 360 are included too.

Not affected: Manual CPC and Target Impression Share bid strategies are untouched. Campaigns using campaign-total budgets (rather than daily budgets) also won't see a change in behavior.

Portfolio bidding and shared budgets
If you're running portfolio bid strategies or shared budgets, any target adjustments need to happen at the portfolio or shared-budget level, not the individual campaign level. In shared budgets that are constrained, the impact is spread across every campaign in the group. For how this fits into a broader cross-channel paid strategy, the portfolio-level view matters more than ever when bidding targets are being enforced this strictly.

Quick answers

Will Google change my targets or budgets for me?
No. Google has confirmed it won't automatically adjust bidding targets or daily budgets. Every action here is manual.

Will this hurt traffic quality?
Google's position is that the system will keep pursuing as many conversions as possible at whatever target you set; the change affects how strictly that target is enforced under budget constraints, not the underlying quality signals used to bid.

Does this affect campaigns that aren't budget-limited?
No. This update specifically targets campaigns in a "Limited by budget" status. Unconstrained campaigns, and campaigns using Manual CPC or Target Impression Share, aren't affected.

Can I still change targets after August 17?
Yes, at any time, before or after the change. Smart Bidding reacts to target adjustments in real time. For the complete paid marketing framework including how Smart Bidding fits into a full-funnel paid strategy, download the Complete Paid Marketing Guide 2026.