As Minnesota faces a federal investigation, U.S. Rep. Michele Bachmann is calling for greater transparency and closer auditing of state and federal Medicaid programs.Bachmann's call, mirroring bipartisan legislation being prepared in the Minnesota House and Senate, comes in the midst of a federal probe into whether the state artificially inflated the premium rates on its low-income health insurance program. "We as lawmakers have an obligation to ensure that Minnesota's payment and oversight practices are both accountable and transparent," said Bachmann, appearing at a press conference at the state Capitol Monday morning.She said she was concerned about the "massive reserves" that have been accumulated by the four HMOs that manage Minnesota's health Medicaid program.The state's Medicaid books have never been audited, Bachmann said, and "this lack of oversight creates a climate of complacency." She said she would be reaching out to congressional Republicans and Democrats alike to push legislation that would call for independent audits of the billions of dollars flowing to health care for millions of low-income Americans."It's not a partisan issue," said Bachmann, who nevertheless did not include any Democrats in her hastily-arranged press conference. She said she has no reason to believe the state or its HMOs are misusing the funds, but until there is an audit, there's no way to say for sure.Amid calls for bipartisan cooperation and unity on the issue, she took a few swipes at the Obama administration's health care affordability act -- or "Obamacare," as she called it. Bachmann said the administration's policies would balloon Medicare's coverage, which would make proper oversight all the more urgent.The situation has already prompted Republicans and DFL members of the Minnesota House and Senate to prepare legislation calling for independent audits of the Medicare fund."It's about making sure people use taxpayer money properly. We want to make sure we pay for what we get and get what we pay for," said state Sen. Sean Nienow, R-Cambridge, who introduced a Medicaid audit bill last week.Nienow estimates it would cost about $700,000 for a forensic accounting firm to comb through the state's books in search of overpayments, accounting errors and other factors that could bleed money away from the taxpayers.The House version of thebill,calling for annual financial audits of managed care plans, was introduced Monday by sponsoring Reps. Steve Gottwalt, R-St. Cloud, and Carolyn Laine, DFL-Columbia Heights, and a raft of other lawmakers from both parties.Bachmann, who has kept a low profile since dropping out of the 2012 presidential race, brushed aside questions not related to her health care proposal.