; and (B) include, among the standards of performance— (i) a reduction in the recidivism rate of offenders transferred to the Residential Reentry Center; and (ii) an annual evaluation of these outcomes; (2) require that new or renewed contracts with providers of Residential Reentry Centers meet the standards of performance-based contracting; (3) review existing contracts with providers of Residential Reentry Centers prior to renewal and update as necessary to reflect the standards of performance-based contracting; and (4) ensure performance-based contracts are actively managed to meet the standards of performance-based contracting. (b) Exceptions In those cases where it would not be cost effective to use performance-based contracting standards, the Director of the Bureau of Prisons shall provide an explanation for this determination to the Attorney General, who may exempt a contract from the requirements outlined in subsection (a)(2). Each exemption must be approved in writing by the Attorney General before the Director of the Bureau of Prisons enters into the contract. (c) Definitions In this section the following definitions apply: (1) Performance-based contracting The term performance-based contracts means contracts that accomplish the following: (A) Identify expected deliverables, performance measures, or outcomes