Regulatory Flexibility Improvements Act of 2003

Regulatory Flexibility Improvements Act of 2003 - Revises the Regulatory Flexibility Act. Defines the "economic impact" of a rule to include any economic effects on small entities. Includes tribal organizations within the definition of "small governmental jurisdictions." Redefines a "small organization."

Requires initial and final regulatory flexibility analyses: (1) to describe alternatives or steps taken, respectively, that maximize any significant beneficial economic impact on small entities; and (2) for revisions to land management plans, rules made on the record after opportunity for an agency hearing, and interpretive rules involving the internal revenue laws that impose a recordkeeping requirement.

Requires initial analyses of a proposed rule to contain a detailed statement (1) of the reasons why a description of duplicative, overlapping, or conflicting Federal rules could not be provided; and (2) estimating the cumulative economic impact on small entities beyond that already imposed on the class of small entities by the agency or explaining why such an estimate is not available.

Requires that final analyses include the agency's response to any comments filed on a rule by the Chief Counsel for Advocacy of the Small Business Administration and a detailed statement of any changes made as a result. Requires publication of analyses on agency websites.

Repeals provisions setting forth procedures for waiving or delaying completion of requirements for analyses.

Sets forth requirements for a report by the Chief Counsel, after a review panel is convened, assessing the impact of certain proposed rules on small entities and discussing the impact of alternatives.

Requires publication by each agency of a new plan for the periodic review of its rules that have a significant impact on a substantial number of small entities to determine whether such rules should be continued, changed, or rescinded.

Requires the Chief Counsel to issue rules governing agency compliance with the Act and authorizes the Chief Counsel to intervene in agency adjudications and inform the agency of the impact of its decision on small entities.