; (B) contain interoperable standards developed and maintained by intergovernmental partnerships, such as the National Information Exchange Model; (C) incorporate interoperable standards developed and maintained by Federal entities with authority over contracting and financial assistance; (D) be consistent with and implement applicable accounting principles; (E) be implemented in a manner that is cost-effective and improves program efficiency and effectiveness; and (F) be capable of being continually upgraded as necessary. (3) Rule of construction Nothing in this subsection shall be construed to require a change to existing data exchange standards found to be effective and efficient. . (b) Effective date Not later than the date that is 24 months after the date of the enactment of this section, the Secretary of Health and Human Services shall issue a proposed rule that— (1) identifies federally required data exchanges, include specification and timing of exchanges to be standardized, and address the factors used in determining whether and when to standardize data exchanges; and (2) specifies State implementation options and describes future milestones.