1. Short title This Act may be cited as the Agency Accountability Act of 2023 . 2. Statutory authority for rulemaking (a) Definitions In this section, the terms agency and rule have the meanings given those terms in section 551 of title 5, United States Code. (b) Statutory authority for rulemaking Section 553 of title 5, United States Code, is amended— (1) in subsection (b)— (A) by amending paragraph (2) to read as follows: (2) a reference to— (A) the specific provision of law that provides the agency with regulatory authority over the subject matter area affected by the rule; and (B) the specific provision of law, including any relevant statutory language, under which the rule is proposed; ; and (B) in paragraph (3)(B), by inserting and the specific references described in paragraph (2) after therefor ; and (2) by adding at the end the following: (f) When publishing a final rule in the Federal Register, including any rule for which a notice of proposed rulemaking is not required to be published, an agency shall include the references described in subsection (b)(2). . (c) Notice regarding statutory authority If an agency imposes a fine or other penalty on an individual related to the violation of a rule, the agency shall inform the individual of the specific statutory provision of law that forms the basis of the rule that the individual is accused of violating. (d) Affirmative defense It shall be an affirmative defense against an alleged violation of a rule for a defendant in any administrative proceeding of an agency, or before a court of the United States, if an individual of ordinary intelligence could not anticipate from the statutory language of a provision of law purported to form the basis for the rule in question that the conduct of the individual would be unlawful.