Capital Requirements Directive IV. The legislative package known as CRD IV introduces significant reforms to the EU’s capital requirements regime for credit institutions and investment firms. CRD IV replaced the previous Capital Requirements Directive with a new directive and regulation: the CRD IV Directive (2013/36/EU) and the Capital Requirements Regulation (or the CRR) (Regulation 575/2013). CRD IV, in conjunction with the CRR, implements the key Basel III reforms, including amendments to the definition of capital and counterparty credit risk and the introduction of a leverage ratio and liquidity requirements. Member states were required to transpose the CRD IV Directive and apply its provisions from January 1, 2014.