A federal judge has determined that Compact of Free Association migrants in Hawaii must receive full medical benefits Dec. 15. The ruling could cost the state upwards of $15 million a year.

In July, the Department of Human Services made significant changes to health care provided to Micronesian immigrants, providing them a cheaper and more limited program than the one available for U.S. citizens under Medicaid. The migrants challenged the implementation, called Basic Health Hawaii, which among other things, restricted coverage to 12 doctors’ visits per year and four prescription medications.

Because of strategic treaties made between the U.S. and Micronesia in the 1980’s, the Pacific islanders can travel freely to the U.S. and are eligible to receive the same services and benefits as American citizens.

The injunction issued Monday by Judge Michael Seabright determined that the changes made by the DHS were illegal and that irreparable harm could come to the migrants if they’re not granted access to the same state Medicaid program as all U.S. citizens in Hawaii.

The lawsuit was filed by the nonprofit Lawyers for Equal Justice and the firms Alston Hunt Floyd & Ing and Bronster Hoshibata.

“A preliminary injunction will effectively maintain the status quo that existed before Defendants implemented BHH for COFA Residents,” Seabright wrote in issuing the injunction. “In comparison, Plaintiffs will suffer irreparable harm without a preliminary injunction because they would be left without adequate medical coverage, which will force them to pay for treatment on their own or completely forego the treatment. In contrast, Defendants will incur the same costs and lose only the “cost savings” that they intended to receive as a result of switching COFA residents over to BHH. While the money Defendants save in implementing BHH is significant, it does not outweigh the physical and financial harm caused to COFA Residents.”

The ruling will cost the state upwards of $15 million per year, said Paul Alston, one of the lawyers on the case.

The lawsuit was one of more than a dozen Gov. Neil Abercrombie inherited from previous governors. Including the COFA ruling, Abercrombie’s administration could be on the hook for legal damages in excess of $200 million.