Which set of specifications should be used for U.S. specific implementation?
The EMV specifications are produced and managed by EMVCo. This is the central global organization and the specifications apply globally; there is no U.S. version of these specifications.
The U.S. does have a specification for U.S. debit transactions which is unique to the U.S. market. This was necessary to support the Durbin Amendment requirement for merchant selection of their preferred routing for U.S. debit PIN transactions made at the POS. Accordingly the EMV Migration Forum Debit Working Committee documented a solution that was agreed on across the industry for adoption. This was published in the U.S. Debit EMV Technical Proposal white paper.
Individual processors supporting this solution and, in particular, market verticals such as parking will provide you with their detailed specifications in relation to support of this U.S. debit solution. We suggest you contact your payment processor to discuss this document with them directly. You can get information from each of the payment brands at their websites: