GAO-13-430, Medicare Program Integrity: Few Payments in 2011 Exceeded Limits under One Kind of Prepayment Control, but Reassessing Limits Could Be Helpful, May 09, 2013 … Read more: GAO-13-430, Medicare Program Integrity: Few Payments in 2011 Exceeded Limits under One Kind of Prepayment Control, but Reassessing Limits Could Be Helpful, May 09, 2013