Regulatory Flexibility Improvements Act of 2013

Defines "small organization" for purposes of RFA.

(Sec. 3) Requires each federal agency to include in its regulatory flexibility agenda a brief description of the sector of the North American Industrial Classification System that is affected by a proposed agency rule that is likely to have a significant economic impact on a substantial number of small entities.

(Sec. 4) Requires a detailed statement in an initial regulatory flexibility analysis to include: (1) an estimate of the additional cumulative economic impact of the proposed rule on small entities, and (2) a description of any disproportionate economic impact on small entities or a specific class of such entities.

Requires an agency, in developing an initial and final regulatory flexibility analysis, to provide: (1) a quantifiable or numerical description of the effects of a proposed or final rule and alternatives to such rule, or (2) a more general descriptive statement and a detailed statement explaining why quantification is not practicable or reliable.

(Sec. 5) Repeals provisions allowing a waiver or delay of the completion of an initial regulatory flexibility analysis. Requires the Chief Counsel for Advocacy of the Small Business Administration (SBA) to issue rules governing federal agency compliance with RFA requirements. Authorizes the Chief Counsel to modify or amend such rules, to intervene in agency adjudication relating to such rules, and to inform an agency of the impact of its rulemaking on small entities.

(Sec. 6) Revises requirements for agency notification of the SBA Chief Counsel for Advocacy prior to the publication of any proposed rule. Requires agencies to provide the Chief Counsel with: (1) all materials prepared or utilized in making the proposed rule, and (2) information on the potential adverse and beneficial economic impacts of the proposed rule on small entities.

(Sec. 7) Modifies requirements for the periodic review of agency rules affecting small entities to require publication of a plan for review and placement of such plan on the agency website not later than 180 days after the enactment of this Act.

(Sec. 8) Provides for judicial review of an agency final rule for compliance with RFA requirements after publication of such rule.

(Sec. 9) Amends the federal judicial code to grant exclusive jurisdiction to the U.S. Courts of Appeals to review all final rules promulgated by the SBA Chief Counsel for Advocacy governing agency compliance with the RFA.

(Sec. 10) Amends the Small Business Act to authorize the SBA Chief Counsel for Advocacy to specify detailed definitions or standards by which a business may be determined to be a small business (size standard) for purposes of all enactments other than the Small Business Act or the Small Business Investment Act of 1958 (for which only the Administrator is authorized to specify small business size standards). Allows a party seeking judicial review of a rule that includes a definition or size standard approved by the Chief Counsel for Advocacy to join the Chief Counsel as a party in an action for such review.

(Sec. 12) Amends the Small Business Regulatory Enforcement Fairness Act of 1996 to require federal agencies, in developing small entity compliance guides, to solicit input from affected small entities or associations of small entities.

(Sec. 13) Requires the Comptroller General, not later than 90 days after the enactment of this Act, to complete and publish a study that examines whether the SBA Chief Counsel for Advocacy has the capacity and resources to carry out the duties of Chief Counsel under this Act.