Democratic attorneys general from Michigan, Colorado, Nevada and Iowa are seeking to intervene in a lawsuit to protect the Affordable Care Act.
That's after a judge declared it unconstitutional.
A federal judge in Texas struck down the Affordable Care Act last month.
But provisions of the health care law will remain in effect while the case is being appealed.
Michigan attorney general Dana Nessel made the announcement Thursday.
Fellow Democrat, Governor Gretchen Whitmer supports the move.
She said in a press release that if the decision is upheld, it'll be harder for Michigan families to get access to healthcare.