Congressional investigators looking into Minnesota's Medicaid program have asked for more information from state officials.
Republicans from both the House and Senate say they're concerned the state has wrongly collected hundreds of millions of dollars in federal Medicaid payments.
Last year, UCare gave the state a $30 million donation that the HMO described as an overpayment from the joint federal and state insurance program for low-income people.
Under pressure from Congress, Minnesota ultimately shared half the money with the federal government.
In a recent letter, Iowa Sen. Chuck Grassley and California U.S. Rep. Darrell Issa demanded more information from state Human Services Commissioner Lucinda Jesson. She testified before a House panel in April and later provided written responses to their questions.
A DHS spokesman says the agency has acted in good faith and that the payments investigators are interested were set by the Pawlenty administration.