Federal rulemaking is an important mechanism through which the federal government implements policy. Federal agencies issue regulations pursuant to statutory authority granted by Congress. Therefore, Congress may have an interest in performing oversight of those regulations, and measuring federal regulatory activity can be a useful way for Congress to conduct that oversight. The number of federal rules issued annually and the total number of pages in the Federal Register are often referred to as measures of the total federal regulatory burden. Certain methods of quantifying regulatory activity, however, may provide an imperfect portrayal of the total federal rulemaking burden. For example, the number of final rules published each year is generally in the range of 2,500-4,500, according to the Office of the Federal Register. While some of those rules may have substantial economic, legal, or policy effects, many of them are routine in nature and impose minimal regulatory burden, if any. The Federal Register provides documentation of the government's regulatory and other actions, and some scholars, commentators, and public officials have used the total number of Federal Register pages each year as a measure for the total amount of regulatory activity. Because the Federal Register has been in print since the 1930s, the number of pages can be useful for cross-time comparisons. However, the total number of Federal Register pages may not be an accurate way to measure regulatory activity for several reasons. For example, the Federal Register contains many other items, not all of which are related to regulations. This report serves to inform the congressional debate over rulemaking by analyzing different ways to measure federal rulemaking activity. The report begins with a brief overview of how agencies issue rules, identifying the most significant statutory requirements, executive orders, and guidance documents that comprise the rulemaking process. The report then provides data on and analysis of the total number of rules issued each year, as well as information on other types of rules, such as "major" rules, "significant" rules, and "economically significant" rules. These categories have been created by various statutes and executive orders containing requirements that may be triggered if a regulation falls into one of the categories. For example, if a rule is designated "economically significant" under Executive Order (E.O.) 12866, the issuing agency is generally required to perform a cost-benefit analysis and submit the rule for review to OMB's Office of Information and Regulatory Affairs (OIRA). When available, data are provided on each type of rule. Finally, the report presents data on the number of pages and documents in the Federal Register each year and analyzes the content of the Federal Register . When Congress enacts legislation, it frequently delegates rulemaking authority to federal agencies. Regulations issued by agencies are often the means through which specific requirements are then established. Regulations must be issued pursuant to statutory authority, and the process under which agencies issue regulations is governed by numerous statutory requirements and executive orders. In addition, OMB has issued guidance to agencies detailing how some of those requirements should be met. This section of the report briefly describes the significant statutory and executive requirements and guidance documents. The most significant statute governing the rulemaking process is the Administrative Procedure Act of 1946 (APA). The APA defines a rule as "the whole or part of an agency statement of general or particular applicability and future effect designed to implement, interpret, or prescribe law or policy." The APA established standards for the issuance of rules using formal rulemaking and informal rulemaking procedures. Informal rulemaking, also known as "notice and comment" rulemaking or "Section 553" rulemaking, is the most common type of rulemaking. When issuing rules under the APA, agencies are generally required to publish a notice of proposed rulemaking (NPRM) in the Federal Register , take comments on the NPRM, publish a final rule in the Federal Register , and provide for at least a 30-day waiting period before the rule can become effective. The APA specifically authorizes any federal agency to dispense with its requirements for notice and comment if the agency for good cause finds that the use of traditional procedures would be "impracticable, unnecessary, or contrary to the public interest." The APA also provides a good cause exception for the 30-day waiting period between the publication of a final rule and its effective date. While the APA's notice and comment procedures comprise the general structure of the rulemaking process, a number of other statutory requirements have been added to the process in the decades since enactment of the APA. The Paperwork Reduction Act (PRA), originally enacted in 1980, established a process under which agencies have to consider the paperwork burden associated with regulatory and other actions. Under the PRA, agencies generally must receive approval from OIRA for information collections from 10 or more nonfederal "persons." The Regulatory Flexibility Act (RFA), also originally enacted in 1980, requires regulatory flexibility analyses for proposed and final rules that will have a "significant economic impact on a substantial number of small entities" (SEISNSE). Other provisions of the RFA require that certain agencies convene advocacy review panels for rules that may have a SEISNSE to solicit feedback from affected entities and that agencies reexamine rules with a SEISNSE to determine whether any changes to or repeal of the rules may be necessary. Title II of the Unfunded Mandates Reform Act (UMRA) of 1995 added requirements for agencies (other than independent regulatory agencies) to analyze costs resulting from regulations containing federal mandates upon state, local, and tribal governments and the private sector. The analysis requirement in UMRA is triggered when a rule "may result in the expenditure by State, local, and tribal governments, in the aggregate, or by the private sector, of $100,000,000 or more (adjusted annually for inflation) in any 1 year." The Congressional Review Act (CRA), enacted in 1996, established a mechanism through which Congress could overturn federal regulations by enacting of a joint resolution of disapproval. The CRA also requires that "major" rules (e.g., those that have a $100 million effect on the economy) have a delayed effective date of at least 60 days, and that agencies submit their rules to both houses of Congress and the Government Accountability Office (GAO) before the rules can take effect. Since it was enacted, the CRA has been used one time to overturn a rule. In addition to the current statutory requirements for the rulemaking process, Presidents also have issued executive orders and OMB has issued guidance providing requirements and guidelines for agencies to follow when issuing rules. E.O. 12866 , issued by President William Clinton in 1993, calls for OIRA to review "significant" regulatory actions at both the proposed and final rule stage. It also requires agencies to assess potential costs and benefits for "significant" rules, and, for those deemed as "economically significant" regulatory actions, agencies are required to perform a cost-benefit analysis and assess the costs and benefits of "reasonably feasible alternatives" to the planned rule. Furthermore, under E.O. 12866, agencies generally must "propose or adopt a regulation only upon a reasoned determination that the benefits" of the rule "justify its costs." E.O. 12866's requirements for OIRA review and cost-benefit analysis do not apply to independent regulatory agencies. To provide guidance to agencies on what to include and consider in their cost-benefit analyses of rules, OMB issued OMB Circular A-4 , a document that describes "best practices" for agencies' regulatory impact analyses. OMB, under President George W. Bush, also provided guidelines for agencies to follow when issuing guidance documents. President Barack Obama has issued several executive orders on rulemaking, and his Administration has issued a number of guidance documents for agencies on how best to issue rules. Most importantly, E.O. 13563 reaffirmed many of the principles of E.O. 12866 and instructed agencies to conduct a retrospective review of their regulations. Following the issuance of E.O. 13563, President Obama issued E.O. 13579 , requesting that independent regulatory agencies also participate in the retrospective reviews. Table 1 presents the approximate number of rules by year since 1976, the first year for which the Office of the Federal Register has data available. The number provided in the table for each year is the number of documents published in the final rules section of the Federal Register . Although the number of regulations issued each year is generally in the thousands, many of those regulations deal with routine matters. For example, a rule issued on April 2, 2013, by the U.S. Coast Guard provided notice of a "temporary deviation from the operating schedule that governs the Third Street Drawbridge across the China Basin, mile 0.0, at San Francisco, CA. The deviation is necessary to allow the public to cross the bridge to participate in the scheduled CycleSF, a community event." Because the change is considered a rule but only has a temporary effect, it does not make any changes to the Code of Federal Regulations (C.F.R. ), which is the comprehensive codification of permanent rules and regulations. Captured under the definition of a rulemaking in the APA, such items are published in the "Rules and Regulations" section of the Federal Register . The number of regulations issued each year includes both new regulations as well as deregulatory actions. Under the APA, a "rulemaking" is defined as "the agency process for formulating, amending, or repealing a rule," which means that agencies must undertake a regulatory action whenever they are issuing a new rule, changing an existing rule, or eliminating a rule. Therefore, not all of the regulations counted in the table above are necessarily new regulatory actions issued by agencies. Some of them could be minor amendments, including technical corrections without substantive change, or they could even include regulatory actions in which agencies are getting rid of regulations or attempting to make regulations less burdensome on the public.