The number of Minnesotans on Medicaid shot up at nearly twice the national rate over the past two years, while state costs soared by 40 percent to surpass $4 billion for the first time. There now are about 733,000 Minnesotans in the state-federal health insurance program for the poor -- called Medical Assistance in Minnesota -- an increase of 125,000 in two years, according to a new federal study.

The Dayton administration is asking the federal government to approve changes to Minnesota's Medicaid program that could save the state $151 million over five years, the Pioneer Press reports. Some of the savings would come through a proposal that asks the federal government to pay for state costs in mental health care, which the feds may not go for, one observer says.

Two powerful members of Congress sent a sharply worded letter to Minnesota Human Services Commissioner Lucinda Jesson, KSTP reports. They want Jesson to answer some pointed questions about Minnesota's $4 billion Medicaid program. Sen. Charles Grassley, R-Iowa, and Rep. Darrell Issa, R-California, fear the state has improperly received roughly $500 million in federal Medicaid reimbursements in the past decade. Jesson has said an independent auditor will look into it.

Minnesota Human Services Commissioner Lucinda Jesson took aggressive questions from lawmakers of both parties on her visit to Capitol Hill. Jesson was in Washington to defend Minnesota's handling of Medicaid, joint program of the state and federal governments.

Republicans in the U.S. House and Senate have asked for more information from Minnesota about its Medicaid program. State Human Services Commissioner Lucinda Jesson already traveled to Capitol Hill to testify in person as Congress looks into possible overpayments. The insurance program for low-income Minnesotans is run jointly by the state and federal governments.

Minnesota is the first state to gain federal approval of a new system of paying hospitals and clinics that treat Medicaid patients. Officials say the system will reward providers that keep patients healthier and cut costs. When hospitals succeed in saving the taxpayer-funded program money, some of the savings will be shared with the hospitals.

With her presidential campaign behind her, 6th District Michele Bachmann hosted a press conference calling for routine audits for state and federal low-income health insurance programs. The proposal comes after word that Minnesota is part of a federal probe into the possibility the state inflated premiums, increasing reimbursements for HMOs.

The Pioneer Press reports federal officials are looking into whether a state agency wrongly received federal funds in the course of operating the state's Medical Assistance insurance program.