"Although Rev. Proc. 2015-27 will bring about changes to the procedures of the EPCRS, it is important to note that it serves only as a modification, and the latter Revenue Procedure does not supplant the former. Thus, in order to properly correct any errors, a plan sponsor still must follow the rules set forth in Rev. Proc. 2013-12, as modified by the recent IRS guidance. The most significant changes are ... [1] Clarification to the correction rules on overpayment failures ... [2] Extended period for self-correction of 415(c) failures... [3] Reduced Voluntary Compliance Program (VCP) fees."