Construction backlogs rose to their highest point in nearly a year in April, signaling that contractors’ pipelines continue to grow despite economic uncertainty.

Data centers alone are disproportionately responsible for this rise in committed construction contracts, a new report found, with participation in the data center boom separating the haves from the have-nots.

The Associated Builders and Contractors Construction Backlog Indicator rose to a 10-month high of 8.8 months in April. The metric, a measure of how many months of contracted work construction firms have yet to complete, rose 0.2 months from March and 0.1 months from April 2025.

The data shows a split between large contractors and their smaller counterparts.

Backlog surged for firms with more than $100M in annual revenue, a 2.2-month year-over-year jump. However, for all other contractors, the backlog numbers were smaller than they were a year ago.

Data centers are largely responsible for this divide, according to ABC Chief Economist Anirban Basu.

“While backlog surged to a 10-month high in April, the industry’s recent momentum is highly concentrated among a subset of contractors,” Basu said in a statement. “Booming data center construction has almost exclusively benefited the largest ABC members.”

ABC found 42% of contractors with more than $100M in annual revenue are under contract to work on data center projects, compared to just 7% of contractors who fall beneath that threshold.

And there is a stark backlog divide between contractors working on data center projects and those that aren’t: Firms with data center contracts have an average backlog of 12.2 months, while all other contractors have a backlog of just 8.3 months.

Still, the survey suggests contractors large and small remain broadly optimistic that growth will accelerate in the months ahead, despite weakening overall construction spending and rising costs for materials and fuel. Just 1 in 5 respondents said they expect profit margins to decrease over the next six months — the lowest share since January 2025.

Contractors also reported optimism regarding sales and future staffing levels, signaling confidence that demand will remain resilient in the coming months.