Amid legal and ethical concerns, Medicaid officials attempted to block the transfer of sensitive data, but top advisers to Health Secretary Robert F. Kennedy Jr. ordered its release to the Department of Homeland Security (DHS).

The Trump administration has provided DHS with personal data of millions of Medicaid enrollees, including their immigration status, raising significant privacy and legality concerns.

Former officials have criticized this unusual data sharing, emphasizing that the Centers for Medicare and Medicaid Services (CMS) typically does not share personal health data with other departments, particularly not with DHS.

In California, Governor Gavin Newsom announced a freeze on enrollment in the state's Medicaid program for non-U.S. citizens due to budget constraints, while Illinois plans to terminate its program for approximately 30,000 individuals in July.

Critics are concerned that this data sharing could negatively impact migrants' applications for green cards or citizenship.

The data transfer was part of a review initiated by CMS, prompted by Trump's executive order aimed at ending taxpayer subsidization of unauthorized immigration, which involved states like California, Illinois, and Washington.

The data set includes sensitive information such as names, addresses, social security numbers, and immigration status of enrollees from states where non-U.S. citizens can enroll in Medicaid using state funds.

Experts warn that the shared information could not only assist authorities in locating migrants but also undermine their chances of obtaining green cards or citizenship if they have received Medicaid benefits.

This review by CMS aims to ensure that federal funds are not used for individuals with 'unsatisfactory immigration status,' as mandated by a February 2025 executive order from Trump.

Governor Newsom's office has expressed serious concerns about the potential misuse of this data during federal immigration raids, highlighting its implications for vulnerable communities.

While all states are required to provide emergency Medicaid services to non-U.S. citizens, some states, including California, allow undocumented immigrants to enroll in Medicaid without federal funding, a practice contested by the Trump administration.

A spokesperson for the U.S. Health and Human Services (HHS) claimed that the data sharing was legal and necessary to ensure Medicaid benefits are reserved for those lawfully entitled to them, despite concerns about its impact on future data sharing.