On August 17, 2026 Google will change how Target CPA and Target ROAS behave for campaigns that are constrained by budget. If your Search, Shopping, Performance Max or certain Demand Gen campaigns are flagged “Limited by budget,” Smart Bidding will stop “overperforming” those targets and instead steer performance closer to the numeric target you entered. That simple shift can materially change efficiency, volume and bidding outcomes — so run a focused audit now.

Why this matters

Before the update, budget-constrained campaigns could deliver results well below (for tCPA) or above (for tROAS) the stated target — and many teams used that gap intentionally to squeeze efficiency from a fixed budget. From August 17, Google will treat the target as the optimization objective rather than as a de facto spending control. For campaigns where the current target no longer reflects the outcome you want, this will require action.

What’s changing — and what’s not

  • The change takes effect August 17, 2026.
  • It applies only to budget-limited campaigns using Target CPA or Target ROAS across Search, Shopping, Performance Max, Demand Gen, Travel and Search Ads 360, and to Demand Gen campaigns in Display & Video 360.
  • Campaigns that are not limited by budget are unaffected.
  • App, Video Reach and Video View campaigns are excluded. Google says Hotel and Display campaigns already optimize toward the entered target.
  • Google released a Bid Target Adjustment Tool on July 6, 2026 to help advertisers identify affected campaigns and review targets before the deadline.

Google’s example is literal: if a campaign’s Target CPA is $10 but its recent actual CPA is $5, the campaign will deliver more closely to $10 after the change. Google expects advertisers who want to preserve a lower CPA to update the target to that lower number.

Where the industry debate comes from

Practitioners split on whether a bidding target should represent the exact performance objective or also function as a lever inside a budget-limited strategy. Some agencies intentionally set targets above or below recent performance to preserve efficiency under a fixed budget. Others insist targets should match the business outcome you want Smart Bidding to pursue. Google’s update pushes accounts toward the latter approach.

Practical audit: what to check before Aug 17

Focus your effort. Start with campaigns that use Target CPA or Target ROAS and show a sustained “Limited by budget” status. For each affected campaign, run these checks:

  1. Confirm the budget constraint is persistent. Is the campaign limited for weeks or months, or just occasional days? Prioritize persistent cases.
  2. Measure the gap between target and recent actuals. Review performance across a full conversion cycle. Large, consistent gaps are where the change will matter most.
  3. Decide whether the current target represents the business outcome. If your business wants to preserve the lower CPA or higher ROAS you’ve been getting, update the bidding target to that number. If the target reflects your true acceptable cost or return, keep it and accept the expected shift in delivery.
  4. Verify the root cause. Budget limits may expose structural issues — insufficient budget, overly broad targeting, or creative/landing problems. Changing the bidding target is one option, not always the fix.

Prioritize campaigns with a sizable, persistent divergence between target and actuals. Use Google’s Bid Target Adjustment Tool to identify candidates quickly, then document your rationale before making any change.

What to monitor after changes

After you update targets or leave them unchanged, watch beyond CPA/ROAS. Track CPC, impression share, conversion volume and conversion quality. Some teams may see higher CPCs or different traffic mixes as Smart Bidding aligns to the stated target; others may see reduced volume. Log what you change and the observed outcomes so future audits are faster and evidence-driven.

The August 17 deadline is a practical prompt: treat it as an opportunity to align bidding settings with explicit business goals rather than leaving them to accumulated habit. Audit the high-impact, budget-limited campaigns first, document your decisions, and monitor the metrics that matter to your business.