WASHINGTON — Seven Democratic members of the Senate Finance Committee are seeking answers from Meta over its use of federal research tax credits as the company builds out data centers for artificial intelligence, warning that ordinary construction costs may not qualify for the subsidy. The lawmakers, led by Sen. Ron Wyden of Oregon, the committee’s ranking Democrat, sent a letter to Meta CEO Mark Zuckerberg demanding details about the company’s claims. They questioned whether Meta is treating data center expansion as research and experimentation, rather than claiming credits only for eligible research activity. “The federal research credit can be a useful and necessary tool to support our nation’s innovation economy and cutting-edge research,” the senators wrote. “Subsidizing your A.I. data center build is not close to meeting this standard.” They said any effort to classify the expansion as eligible could represent a significant misapplication of tax law and merits further investigation. The lawmakers’ action follows a report that Meta reduced its tax liability by billions of dollars through the credit. The letter does not establish that the company violated tax law; it asks for an explanation of how Meta is applying the provision. Meta spokesman Andy Stone rejected the criticism, arguing that AI-focused data centers differ from conventional facilities and require extensive testing that cannot be fully simulated. He said the investment fits the kind of domestic innovation Congress intended to encourage when it established the incentives. The research and development credit has long enjoyed broad support in Congress, and Republicans expanded the provisions as part of their 2025 tax law. But the fast-growing cost of tax breaks associated with AI infrastructure is drawing scrutiny: budget forecasters say the claims have become large enough to reduce federal tax receipts. Data centers have also become a prominent issue in the 2026 midterm campaign, as communities and voters weigh the effects of large facilities. Sen. Peter Welch, a Vermont Democrat who signed the Meta letter, separately asked the IRS last week for information on how Meta and other major technology companies use the research credit. The seven senators’ inquiry puts a spotlight on the line between subsidizing genuine technological development and giving tax relief for the infrastructure companies need to operate. Meta maintains its AI data center work crosses that line into experimentation; the lawmakers are asking the company to show why.