HHS has said states have three options: set up their own exchange, work in partnership with the federal government or step back entirely while HHS establishes a "federally facilitated exchange."
The Obama administration has pushed each state to take on at least some control over its exchange, saying each state's insurance market is different. But several Republican governors say they're unwilling to implement "ObamaCare" by creating a state-based exchange, meaning HHS would have to step in.
HHS has released few details about the federal exchange — states aren't sure which costs they'll have to cover if they leave the task up to HHS, Hatch said.
"I respectfully request that the politicization by the Administration of the President's health law end and that the transparency promised by the President be shown by offering the states a complete understanding of their choices and the cost associated with such choices," Hatch's letter states.
It's also unclear, he said, whether HHS will establish a separate federal exchange in each state, and how they will vary from state to state.