The Affordable Care Act (ACA) requires providers including physicians to report and refund known overpayments within 60 days, or, for providers that submit cost reports, by the date the corresponding cost report is due.  The parameters of this mandate are unclear, but the duty to refund overpayments exists regardless.  After summarizing some of the problems with the ACA provision and with CMS’ proposed regulations implementing the statute, we will offer some practical suggestions on compliance.The refund requirement, which has been in effect since March 23, 2010 (the date the ACA became law), is vague in several important particulars.  The lack of certainty, far from discouraging compliance, has left many providers, suppliers and affected health plans scrambling to find and refund overpayments within the 60-day window to avoid hefty penalties.  On February 16, 2012, CMS issued a proposed rule that limited its application to Medicare payments and cleared up some, but not...