(a) In general Except as provided in subsection (b), before promulgating any rule for which a written statement is required under section 1532 of this title , the agency shall identify and consider a reasonable number of regulatory alternatives and from those alternatives select the least costly, most cost-effective or least burdensome alternative that achieves the objectives of the rule, for— (1) State, local, and tribal governments, in the case of a rule containing a Federal intergovernmental mandate; and (2) the private sector, in the case of a rule containing a Federal private sector mandate. (b) Exception The provisions of subsection (a) shall apply unless— (1) the head of the affected agency publishes with the final rule an explanation of why the least costly, most cost-effective or least burdensome method of achieving the objectives of the rule was not adopted; or (2) the provisions are inconsistent with law. (c) OMB certification No later than 1 year after March 22, 1995 , the Director of the Office of Management and Budget shall certify to Congress , with a written explanation, agency compliance with this section and include in that certification agencies and rulemakings that fail to adequately comply with this section. ( Pub. L. 104–4, title II, § 205 , Mar. 22, 1995 , 109 Stat. 66 .)