The defendants1 appeal from the trial court’s decision sustaining the plaintiffs’2 administrative appeal from a decision of the defendant Peter W. Gillies, insurance commissioner. The commissioner suspended the insurance licenses issued by the defendant insurance department to the plaintiffs and imposed fines on the plaintiffs for unlawfully conducting insurance business in violation of General Statutes §§ 38-603 and 38-264,4 and for engaging in business with an insurance company not authorized to do business in Connecticut in violation of General Statutes § 38-70.5
*624The sole issue on appeal is whether the trial court erred in finding that the defendants had not adopted written rules of procedure governing hearings as required by § 4-167 (a) (2)6 of the Uniform Administrative Procedures Act (UAPA).7 We find no error.
Administrative proceedings against the plaintiffs were commenced by service of an amended notice of hearing. The first paragraph of the notice informed the plaintiffs that “[t]he hearing will be conducted in accordance with the procedures set forth in the UAPA (Chapter 54, C.G.S.).” After a hearing, the plaintiffs were found in violation of various sections of the General Statutes. The insurance commissioner accepted and adopted the hearing officer’s findings of fact and conclusions of law. Thereafter, the plaintiffs were fined $4100 and their insurance licenses were suspended for three months.
The plaintiffs appealed to the Superior Court on four grounds. The court held that because the defendant insurance department failed to adopt as a regulation written rules of procedure governing its hearings as *625required by § 4-167 (a) (2), it was “without authority to take administrative action on their charges against the plaintiffs.” The trial court sustained the appeal on this ground alone and deemed it unnecessary to reach the other claimed errors. This appeal by the defendants followed.
A “regulation” is statutorily defined as an “agency statement of general applicability, without regard to its designation, that implements, interprets, or prescribes law or policy, or describes the organization, procedure, or practice requirements of any agency.” General Statutes § 4-166 (7). The defendants maintain that § 38-4-8 of its regulations, which was in effect at the time of the hearing, was a regulation providing adequate “rules of practice setting forth the nature and requirements of all formal and informal procedures available” as required by General Statutes § 4-167 (a) (2).8 The Regulations of Connecticut State Agencies § 38-4-8, at the time of the hearing, provided: “All hearings conducted in the insurance department are conducted in accordance with the requirements of and procedures suggested in Public Act 854 of the 1971 session of the General Assembly, Sections 12 through 17 inclusive, as the same may be amended from time to time. Conferences, interviews and formal hearings conducted or held as a part of the administrative processes of the insurance department are conducted on an informal basis, in accordance with standards designed to meet the purposes to be accomplished by the proceeding.” (Emphasis added.) Regs., Conn. State Agencies § 38-4-8. “Whether administrative action is a regulation does not depend on the label the agency attaches to it or on the procedure giving rise to it .... ‘The test is, rather, whether “a rule has a substantial impact on the rights and obligations of parties who may appear before the agency in the future.” ’ ” *626(Citation omitted.) Eagle Hill Corporation v. Commission on Hospitals & Health Care, 2 Conn. App. 68, 76, 477 A.2d 660 (1984). When a rule passed by an agency has this impact it must comply with the notice and hearing requirements of the UAPA. Cheshire Convalescent Center v. Commission on Hospitals & Health Care, 34 Conn. Sup. 225, 239, 386 A.2d 264 (1977). Thus, the pivotal issue is whether the rule passed by the insurance department in this case had a “substantial impact on the rights and obligations” of parties appearing before the insurance commissioner. The test to be applied in determining whether an administrative action was in fact a regulation, is to examine what the agency actually did in a particular case and how it did it. Id.; see also Salmon Brook Convalescent Home v. Commission on Hospitals & Health Care, 177 Conn. 356, 362, 417 A.2d 358 (1979).
An administrative agency can act only within the bounds of authority granted to it by its enabling statute and within constitutional limitations. It is wholly without power to modify, dilute or change in any way the statutory provisions from which it derives its authority unless the state clearly and expressly grants it that power. Waterbury v. Commission on Human Rights & Opportunities, 160 Conn. 226, 230, 278 A.2d 771 (1971). Although an administrative agency has the statutory power, indeed the obligation, to promulgate rules and regulations, it does not make law. Its rulemaking power extends only to the point of effecting the legislative will as expressed by statute. The UAPA provides uniform rules which guide agencies in the proper execution of their delegated duties. Salmon Brook Convalescent Home v. Commission on Hospitals & Health Care, supra, 363.
This principle is grounded in common sense and simple concepts of fairness. “ ‘The objective is . . . the promulgation . . . of a code governing action and con*627duct in the particular field of regulation so those concerned may know in advance all the rules of the game, so to speak, and may act with reasonable assurance. . . . Persons subject to regulation are entitled to something more than a general declaration of statutory purpose to guide their conduct before they are restricted or penalized by an agency for what it then decides was wrong from its hindsight conception of what the public interest requires in the particular situation.’ ” Adams v. Professional Practices Commission, 524 P.2d 932, 934 (Okla. 1974).
The defendants assert that since § 38-4-8 of its regulations specifically referred to Public Acts 1971, No. 854, §§12 through 17, the department had stated the “rules of the game.” Those sections, now §§ 4-177 to 4-182 of the UAPA, encompass rules relating to notice, evidence, the record, conduct of officials and agency members, and license hearings. The defendants argue that the procedures set forth in the UAPA are sufficiently clear to inform parties appearing before the department of the “rules of the game.” Yet, reason dictates otherwise, for “if the legislature had considered that to be true, it would not have provided in the act for the adoption and filing of rules of procedure.” Monahan v. Board of Trustees, 486 P.2d 235, 239 (Wyo. 1971).
The defendants’ reliance on Cope v. Board of Education, 4 Conn. App. 464, 465, 495 A.2d 718 (1985), is misplaced. Cope is distinguishable from the present case because it involved action by a board of education. Boards of education are specifically excluded from the statutory definition of “agency”9 and are thus exempt from the regulation requirements of the UAPA.
*628The second sentence of § 38-4-8, that the hearings would be “conducted on an informal basis, in accordance with standards designed to meet the purposes to be accomplished by the proceeding,” is fatally vague and uncertain. The trial court was correct in concluding that the section was invalid on the ground that it was an unlawful regulation not promulgated in accordance with the rulemaking provision of the UAPA.
There is no error.
In this opinion, Hull, J., concurred.
Both the insurance department and Peter W. Gillies, insurance commissioner, are defendants in this appeal.
The second plaintiff, Conceptional Services, Inc., formerly known as Options Services, Inc., joins in this appeal.
General Statutes § 38-60 provides in pertinent part: “No person shall engage in this state in any trade practice which is ... an unfair method of competition or an unfair or deceptive act or practice in the business of insurance .... The commissioner shall have power to examine the affairs of every person engaged in the business of insurance in this state in order to determine whether such person has been or is engaged in any unfair method of competition or in any unfair or deceptive act or practice prohibited by sections 38-60 to 38-64, inclusive.”
General Statutes § 38-264 provides in pertinent part: “No person or insurer shall directly or indirectly do any of the acts of an insurance business set forth in subsection (a) of section 38-263 except as authorized by the general statutes. In respect to the insurance of subjects resident, located or to be performed within this state this section shall not prohibit the collection of premium or other acts performed outside of this state by persons or insurers authorized to do business in this state, provided such transactions and insurance contracts are otherwise lawful.”
General Statutes § 38-70 provides: “No person shall, within this state, solicit or procure insurance, except with regard to his own property or per*624son, with or by any insurance company which does not hold a certificate then in force from the commissioner authorizing such insurance company to do such insurance business in this state, or deliver policies or collect premiums of or for any such company; nor shall any person aid in any way in the transaction in this state of any insurance business with or by any insurance company not thus authorized, except to obtain insurance upon his own property or person. Any person who aids any corporation, association or person not authorized to do insurance business in this state in soliciting such business from residents of this state, by means of any advertisement published in this state or by any other means, shall be fined not more than one hundred dollars or imprisoned not more than six months or both.”
General Statutes § 4-167 (a) provides in pertinent part: “In addition to other regulation-making requirements imposed by law, each agency shall: ... (2) adopt as a regulation rules of practice setting forth the nature and requirements of all formal and informal procedures available provided such rules shall be in conformance with the provisions of this chapter
General Statutes §§ 4-166 through 4-189 is the Uniform Administrative Procedures Act.
See footnote 6, supra.
General Statutes § 4-166 provides in pertinent part: “(1) ‘Agency’ means each state board commission, department or officer, other than . . . regional boards of education . ” (Emphasis added.)