Rep. Mike Thompson of California, the top Democrat on the House Ways and Means Tax Subcommittee, and nine other lawmakers sent a letter to Treasury Secretary Scott Bessent seeking an explanation for the delay. The data typically provides a detailed picture of which tax provisions people claimed, how much they paid and how filing outcomes varied by income.

The IRS continues to publish weekly summaries during tax season, including the number of returns processed and refunds issued. But the figures sought by the lawmakers go further, detailing the use of specific tax breaks, changes in reported income among different groups and how many filers owed money when they submitted returns.

Thompson said Republicans had promoted the tax law but that the administration was withholding information that could show who benefited. He argued that the data should be made public regardless of whether it supports the administration’s preferred account of the law.

Critics of the delay say Treasury lacks legal authority to prevent the data’s release. The department had not immediately responded to a request for comment as of Oct. 22.

The withheld figures could help lawmakers and the public evaluate the distributional effects of the tax changes. Without them, a fuller comparison of how the law affected taxpayers at different income levels remains difficult.