Meta cut its federal tax liability by more than $6.6 billion over three years using research credits. Now Democrats on the US Senate Committee on Finance want to know how, and whether AI data centers should qualify at all.

In a letter to CEO Mark Zuckerberg, the senators cite public reports that Meta told the IRS its AI data centers count as "pilot models" under section 41 of the Internal Revenue Code. That section grants a dollar-for-dollar income tax reduction for domestic research and experimental expenditures. The senators wrote that if the reports hold, Meta saved billions on its AI buildout, including hardware and equipment purchases, "in violation of the spirit and, potentially, the letter of the tax law."

Bloomberg first reported the letter.

How big are the numbers?

Meta's regulatory filings show a steep climb in claimed credits:

• $700 million in research credits in 2023
• $2 billion in 2024
• $4 billion in 2025

In 2025, all research credits nationwide cost the government $32 billion. Meta alone took more than 10 percent of that total.

The credits sit alongside an aggressive capital spending program. Meta's capex reached $72.2 billion in 2025, up from $37.2 billion in 2024. The company estimates 2026 capex of up to $145 billion.

What does this change for the buildout?

The core dispute is definitional. The research credit exists to offset experimental work with a high risk of technical uncertainty. It does not cover standard business operations or commercially available technologies already in use. A data center full of purchased servers and networking gear is, on its face, the second category — unless Meta can show the facilities themselves amount to genuine experiments.

The senators put the question directly: "While it remains unclear exactly how Meta was able to reduce its federal tax liability by over $6.6 billion in the last three years using federal research credits, it appears from published reports that a substantial share is by claiming the research credit related to its massive AI data center buildout."

Meta itself has flagged the exposure. Its most recent Annual Report acknowledges "uncertain tax positions" tied to "uncertainties with our research and development tax credits," based on whether Meta's "available documentation corroborating the nature of our activities supporting the tax credits will be sufficient."

Unusual construction in the picture

Some of Meta's data center construction methods break from convention. The company has built facilities in tents — rapid deployment structures made of puncture-resistant, waterproof fabric. Whether such methods support a "pilot model" argument is exactly the kind of question the committee wants answered.

Ten questions, one deadline

The Committee on Finance has set a deadline of the end of October 2026 for Meta to answer ten questions. They include:

• Whether the research tax credits relate to the data center buildout
• Whether Meta consulted EY or other professional accounting firms before claiming the credits
• A justification for each year's research credit claims

Seven senators signed the letter: Sheldon Whitehouse, Catherine Cortez Masto, Ron Wyden, Ben Ray Lujan, Peter Welch and Margaret Wood Hassan of the Finance Committee, plus Elizabeth Warren, ranking member of the Committee on Banking, Housing, and Urban Affairs.

Meta has not yet responded publicly. DCD has reached out to the company for comment.

The stakes run past Meta. If data center buildouts qualify as research, every hyperscaler racing to pour capex into AI infrastructure has a template for similar claims. If they do not, the IRS has a multibillion-dollar correction to make.