The IRS provided Immigration and Customs Enforcement (ICE) with last-known address information for nearly 47,000 people under a controversial data-sharing agreement, according to a new report from the Treasury Inspector General for Tax Administration (TIGTA).
According to TIGTA, last year, ICE asked the IRS for address information tied to more than 1.2 million records. The IRS ultimately provided last-known addresses for approximately 47,000 people after an automated process matched ICE-provided information against IRS records.
TIGTA found problems with the process. According to the watchdog, the IRS developed an automated matching system before releasing the information, but the criteria “were unable to identify and match the records accurately and consistently.” In some instances, records requests that should have been rejected may not have been. In others, possible matches may have failed due to minor formatting differences.
TIGTA did not take a position in its report on whether the IRS-ICE agreement was legal, but focused on the IRS processes and controls for implementing the agreement. Still, the findings are likely to add fuel to existing concerns about the use of IRS data for immigration enforcement.
How The IRS-ICE Agreement Worked
Taxpayer information is generally protected from disclosure under section 6103 of the tax code. That provision broadly bars federal employees from disclosing tax returns and return information unless a statutory exception applies. The IRS relied on one of those exceptions—section 6103(i)(2)—to share limited return information with ICE for nontax criminal investigations.
The data-sharing agreement, signed in April 2025, authorized ICE to request address information for certain individuals. That agreement followed two executive orders by President Donald Trump. One directed the Department of Homeland Security (DHS) to take steps to exclude or remove certain noncitizens subject to exceptions related to serious criminal investigations, prosecutions, or national security interests. Another pushed agencies to make government data easier to share across the executive branch.
The agreement drew immediate scrutiny. House Democrats sought unredacted copies of the agreement from Treasury Secretary Scott Bessent and then-DHS Secretary Kristi Noem, citing concerns that the arrangement could lead to “grave consequences” for taxpayers whose information was shared. A heavily redacted version of the agreement filed in court made it difficult to understand the purpose of the disclosure, agency duties, and the information to be disclosed.
Critics also worried the arrangement would be broader than officials had suggested. Early reports indicated that the IRS would verify immigrants’ names and addresses against tax records, but questions remained about whether other information—such as dependent information or other personal details—could be shared. TIGTA’s report says the IRS stated that it provided only the last-known addresses and no other tax information in response to ICE’s June 2025 request.
A Huge Request With Messy Data
The findings show how difficult it can be to use tax records for a purpose outside ordinary tax administration. According to TIGTA, the name and address fields contained numerous inconsistencies.
The IRS used automated matching to screen the data. However, TIGTA found that the process relied on exact matching in some areas, which created problems. First- and last-name fields could include one name, two names, initials, or combined names, while multiple names could be separated by hyphens, spaces, or no spacing at all. (Those of us with double last names understand the difficulties all too well.)
Some addresses were crammed into a single field and included abbreviations, punctuation, special characters, missing street numbers, missing city or state information, or nonexistent ZIP codes. For example, slight differences, such as “Street” versus “St,” “Avenue” versus “Ave,” or spacing variations in a name, could prevent a match.
The process also checked for blank addresses and whether an address contained a five- or nine-digit number that might be a ZIP code. But TIGTA found that the system did not verify whether the number was actually a valid ZIP code. Nor did it reliably distinguish a ZIP code from a five-digit street number (like 12345 Main Street). As a result, addresses that included strings such as “00000” or “99999” or otherwise indicated that no address had been provided could still pass the initial screen.
IRS Later Confirmed Some Concerns
After TIGTA raised concerns with IRS officials in late 2025, the IRS manually reviewed the data and confirmed the invalid address matches. In February 2026, an IRS official acknowledged that the agency may have provided last-known addresses when ICE had provided incomplete or insufficiently populated address information for about 5% of the approximately 47,000 matched individuals.
In January 2026, the IRS notified DHS of the matching problem and asked the agency to help fix it. The IRS also informed TIGTA that, pending litigation, DHS and ICE had confirmed they would not use or act on the IRS data.
Safeguard Concerns At ICE
The report raised a separate concern. Agencies that receive federal tax information must follow IRS security rules. The IRS checks compliance through safeguard reviews and issues reports identifying problems agencies must fix. TIGTA found that several issues from an earlier IRS review of ICE remained unresolved when the IRS transferred the data. The details are heavily redacted, but TIGTA said several of the unresolved findings could have affected ICE’s effectiveness in protecting federal tax information.
TIGTA also found that ICE failed to file required corrective action plans for several time periods. ICE submitted a corrective action plan in July 2025, but TIGTA said it did not include implementation dates for some actions. As of May 2026, the IRS said ICE had not provided its updated January 2026 corrective action plan, and a safeguard review site visit had been postponed (allegedly due to a partial government shutdown).
A Broader Push To Use IRS Resources
The report comes amid broader turmoil at the IRS over data access and immigration enforcement. Earlier in 2025, DHS asked Treasury to deputize IRS personnel to assist with immigration-related efforts, including employer audits and financial audits of businesses suspected of employing unauthorized workers. The language appeared to target IRS Criminal Investigation (CI) personnel.
CI eventually saw a significant shift to immigration enforcement. By June 2025, 250 CI employees had reportedly been reassigned to ICE. By September, that number had reportedly grown to 1,700, a major redeployment for an agency that had about 3,000 employees at the end of fiscal 2025, including roughly 2,200 special agents.
That context is important because the TIGTA report notes that ICE told the IRS it would continue advising staff not to receive federal tax information directly. Instead, ICE said staff were instructed to access such information through U.S. Attorney’s Offices or by inviting an IRS-CI agent to work jointly on an investigation. TIGTA said it could not verify that process because no additional information had been provided.
(Earlier this year, then-outgoing CI Chief Ficco said that CI was pulling back agents from immigration and getting them back to CI’s core mission of following the money in tax and other fraud cases.)
Leadership Churn At The IRS
The IRS has also experienced significant leadership turnover, with officials leaving their positions. In April 2025, acting IRS Commissioner Melanie Krause resigned after only a few weeks. She had stepped in after Doug O’Donnell’s brief tenure as acting commissioner, which followed former Commissioner Danny Werfel’s January 2025 departure. Krause’s exit made her the third commissioner or acting commissioner to leave the agency in less than 80 days.
Conversations that Forbes had with IRS employees at the time suggested they would rather leave their positions than serve in immigration-related roles under the current administration. Krause seems to have taken a similar tack.
The agency’s legal office also became part of the data-access controversy. Acting Chief Counsel William Paul was reportedly demoted after refusing to cooperate with Elon Musk’s Department of Government Efficiency (DOGE) in accessing or sharing taxpayer information with other federal agencies. Those DOGE-related concerns predated the TIGTA report but help explain why taxpayer-data issues have attracted so much attention. DOGE reportedly sought access to the IRS’s Integrated Data Retrieval System (IDRS), a core IRS system that contains returns and other taxpayer information, including bank records. Taxpayers and tax professionals have repeatedly raised concerns about legality and the risk of sensitive information being misused or leaked.
Why Taxpayer Privacy Matters
Before 1976, tax returns were not as tightly controlled, with access more or less delegated by the executive branch. After Watergate-era abuses and concerns that the IRS could be used to target political enemies, Congress made confidentiality the default rule under section 6103.
Taxpayers know that tax returns tell a bigger story than income. They may include information about your children and your employers. They contain your address and sensitive details about your bank accounts, investments, and retirement savings. They may also have information about which charities you support, what kinds of medical expenses you pay, and how your business is doing. That’s why even a taxpayer’s address, when obtained from IRS records, is protected information unless a statutory exception applies.
What TIGTA Did—And Did Not—Find
The TIGTA report does not say that the IRS disclosed full tax returns, bank information, or information about dependents to ICE. It also does not conclude that the IRS-ICE agreement violated the law, nor does it make any formal recommendations (which felt off for a TIGTA report, though it typically withholds recommendations while litigation is pending).
But it did offer the first detailed, official look at how the IRS-ICE agreement worked, and that’s what many taxpayers were focused on. They wanted to know whether information provided to the IRS for tax purposes could be used for something else. Here, as TIGTA’s report shows, the answer depends on how carefully the process is run. In this case, TIGTA found it wasn’t. For the taxpayers caught in the middle, that’s what matters most.
About TIGTA
TIGTA was established in January 1999 by the IRS Restructuring and Reform Act of 1998 to provide independent oversight of IRS activities. Today, TIGTA provides audit, investigative, and evaluation services to promote integrity, efficiency, and economy in the administration of the nation’s tax system. While TIGTA sits organizationally within the Department of the Treasury and reports to the Secretary of the Treasury and to Congress, the agency is considered to be independent.
You can read the TIGTA report here.
