WASHINGTON (8/18/11)--MasterCard plans to implement a two-tiered debit interchange fee structure, and currently plans to keep its existing market-based rate structure in place for credit unions and other financial institutions with under $10 billion in assets, MasterCard Global Head of Public Policy Shawn Miles said during a Wednesday conference call. Miles added, however, the rates are subject to change based on market forces and will be finalized in a few weeks and announced prior to Oct. 1. The call was presented by MasterCard and the Credit Union National Association (CUNA) and featured input from CUNA Chief Economist Bill Hampel and CUNA Deputy General Counsel Mary Dunn. The Fed's final debit interchange rule caps debit interchange fees for issuers with assets of $10 billion or more at 21 cents, and allows an additional five basis points of the value of the transaction to cover fraud losses. An extra penny may be charged by financial institutions that are in compliance with Fed-established fraud prevention standards. Credit unions and other institutions with under $10 billion in assets are exempt from the rule. MasterCard plans to establish its own online debit interchange registration system for its member institutions to denote if they are above or below the $10 billion-asset threshold. The card processor is planning to include in the registry the ability for institutions above $10 billion in assets to certify that they qualify to receive the extra penny for complying with fraud prevention standards. CUNA and MasterCard will both monitor merchants for any signs that they are steering consumers away from using debit cards issued by institutions that are not subject to the cap. CUNA is developing a mechanism for credit unions to report illegal merchant steering behavior. The MasterCard representative also thanked credit unions and CUNA for their efforts to delay and change the debit interchange fee cap legislation, and said that the final rule was significantly improved due to this work. Miles added that MasterCard looks forward to working with CUNA on any future threats to interchange fees. However, CUNA has noted that members of Congress are reticent to take up the interchange debate any time soon, given the controversy that surrounded the issue.