signed Mutual Recognition Agreements with U.S. Customs and Border Protection. (c) Guidelines Not later than 180 days after the date of the enactment of this subtitle, the Commissioner shall develop a schedule and update the guidelines and criteria for validating a C–TPAT participant’s security measures and supply chain security practices under this section. (d) Timeframe To the extent practicable, the Executive Assistant Commissioner shall complete the Tier 2 validation process for a C–TPAT program participant under this section within one year after certification of such participant as a Tier 1 participant. 217. Tier 3 participants (a) In general The Commissioner shall establish a third tier of C–TPAT program participation that offers additional benefits to C–TPAT program participants that are importers or other entity types, in accordance with section 212(b), that demonstrate a sustained commitment to maintaining security measures and international supply chain security practices that exceed the guidelines established for validation as a Tier 2 participant in the C–TPAT program under section 216. (b) Best practices The Executive Assistant Commissioner may designate a Tier 2 C–TPAT program participant as a Tier 3 participant based on a review of best practices in such participant’s international supply chain that reflect a continued approach to enhanced international supply chain security, including— (1) compliance with any additional or updated criteria established by the Commissioner of U.S. Customs and Border Protection under section 213(d) that exceed the guidelines established pursuant to section 216 for validating a C–TPAT program participant as a Tier 2 participant