One of Oregon's coordinated care organizations, FamilyCare, has notified the state it intends to sue over the way health insurance rates are set.
Under Oregon's health care experiment, the federal government has given the state flexibility to sets rates.
For example, last year Portland-based FamilyCare had its rates reduced by about 9 percent. The head of the CCO, Jeff Heatherington, says that translated to a loss of more than $4 million a month - and the state won't tell him why it reduced the rates.
"If the Oregon Health Authority would actually just open up their books and say, 'Look, this is how we did it,'" he said, "we could all look at it and have a discussion.
"But the first thing they did is bury everything deep and won't answer questions."
A spokeswoman for the Oregon Health Authority said the agency can't comment on potential litigation.
The economics of Oregon's 16 CCOs might become clearer at the end of the month, when the state is expected to release financial details.