A federal judge has temporarily blocked the Department of Health and Human Services (HHS) from sharing certain Medicaid data with immigration authorities. U.S. District Judge Vince Chhabria issued a preliminary injunction on August 12, ruling that HHS, through its Centers for Medicare and Medicaid Services (CMS), failed to follow a proper decision-making process before allowing data to be shared with the Department of Homeland Security (DHS).

The case stems from actions taken earlier this year after President Trump assumed office. CMS asked states to provide information on individuals with “unsatisfactory immigration status” and began sharing statistical Medicaid data with DHS. This arrangement eventually developed into a formal agreement that granted immigration authorities direct access to CMS databases, although private health information was not included.

Judge Chhabria found the policy change to be abrupt and poorly considered. He warned that using Medicaid data for immigration enforcement could disrupt healthcare services for vulnerable populations and discourage eligible individuals from participating in the program. His ruling halts data sharing from 20 states, including California and Hawaii, and bars DHS from using data it has already received from those states.

While Chhabria acknowledged that DHS has a legitimate interest in immigration enforcement, he emphasized that any policy shift must be based on a reasoned decision-making process, especially when overturning long-standing practices. In response, HHS defended the data-sharing policy as legal and necessary to ensure Medicaid benefits are reserved for those lawfully eligible.

State attorneys general filed the lawsuit in July, arguing that the policy shift could harm low-income communities and undermine public health. The case will now proceed, as the Trump administration weighs whether to appeal the ruling or revise the policy to meet legal standards.