Congress passed LDA and IRC sections 4911 and 162(e) at different times and for different purposes. LDA, which was enacted in 1995 and became effective on January 1, 1996, requires organizations that lobby certain federal officials in the legislative and executive branches to register with the Secretary of the Senate and the Clerk of the House of Representatives. It also requires lobbying organizations that register to semiannually report expenditures and certain other information related to their lobbying efforts. Congress intended LDA’s registration and reporting requirements to provide greater public disclosure of attempts by paid lobbyists to influence decisions made by various federal legislative and executive branch officials. Unlike LDA, neither IRC section 162(e) nor section 4911 was intended to facilitate the public disclosure of lobbying. IRC section 4911, which was enacted in 1976, provides for a limit on the amount of lobbying by 501(c)(3) organizations and thereby helps clarify the extent to which these public charities can lobby without jeopardizing their tax-exempt status. Section 162(e), as amended in 1993, denies the federal income tax deductibility of certain lobbying expenses for businesses. It does not otherwise place restrictions on lobbying activities. LDA requires lobbying organizations, such as lobbying firms, to register with the Secretary of the Senate and the Clerk of the House of Representatives no later than 45 days after they first make a lobbying contact on behalf of a client. Also, organizations that have employees who lobby on behalf of the organizations—the organizations on which this report focuses—must register under LDA. The lobbying registration includes such information as the registering organization’s name and address; the client’s name and address; the names of all individuals acting as lobbyists for the client; the general and specific issues to be addressed by lobbying; and organizations substantially affiliated with the client, including foreign organizations. An organization that has employees who lobby on the organization’s behalf must identify itself as both the registering organization and the client, because the organization’s own employees represent the organization. LDA includes minimum dollar thresholds in its registration requirements. Specifically, an organization with employees who lobby on the organization’s behalf does not have to register under LDA unless its total lobbying expenses exceed or are expected to exceed $20,500 during the 6 month reporting period (i. e., January through June and July through December of each year). LDA also includes minimum thresholds for determining which employees must be listed as lobbyists in the lobbying registration. Under LDA, to be listed as a lobbyist, an individual must make more than one lobbying contact and must spend at least 20 percent of his or her time engaged in lobbying activities on behalf of the client or employing organization during the 6 month reporting period. An organization must have both $20,500 in lobbying expenses and an employee who makes more than one lobbying contact and spends at least 20 percent of his or her time lobbying before it is required to register under LDA. All organizations that register under LDA must file lobbying reports with the Secretary of the Senate and Clerk of the House of Representatives for every 6 month reporting period. The lobbying reports filed under LDA by organizations that lobby on their own behalf must include the following disclosures: total estimated expenses relating to lobbying activities (total expenses are reported either by checking a box to indicate that expenses were less than $10,000 or by including an amount, rounded to the nearest $20,000, for expenses of $10,000 or more); a three-digit code for each general issue area (such as AGR for Agriculture and TOB for Tobacco) addressed during lobbyists’ contacts with federal government officials; specific issues, such as bill numbers and references to specific executive branch actions that are addressed during lobbyists’ contacts with federal government officials; the House of Congress and federal agencies contacted; the name of each individual who acted as a lobbyist; and the interest of the reporting organization’s foreign owners or affiliates in each specific lobbying issue. Unless it terminates its registration, once a lobbying organization registers, it must file reports semiannually, regardless of whether it has lobbied during the period. Under LDA, lobbying firms that are hired to represent clients are required to use the LDA lobbying definition. However, LDA gives organizations that lobby on their own behalf and that already use an IRC lobbying definition for tax purposes the option of using the applicable IRC lobbying definition (IRC sections 4911 or 162(e)), instead of the LDA lobbying definition, for determining whether the LDA registration threshold of $20,500 in semiannual lobbying expenses is met and calculating the lobbying expenses to meet the LDA reporting requirement. For all other purposes of the act, including reporting issues addressed during contacts with federal government officials and the House of Congress and federal agencies contacted, LDA provides that organizations using an IRC definition must (1) use the IRC definition for executive branch lobbying and (2) use the LDA definition for legislative branch lobbying. By allowing certain organizations to use an IRC definition to calculate lobbying expenses, LDA helps those organizations avoid having to calculate their lobbying expenses under two different lobbying definitions—the LDA definition for reporting under LDA and the applicable IRC definition for calculating those expenses for tax purposes. An organization that chooses to use the applicable IRC definition, instead of the LDA definition to calculate its lobbying expenses, must use the IRC definition for both lobbying reports filed during a calendar year. However, from one year to the next, the organization can switch between using the LDA definition and using the applicable IRC definition. Under LDA, we are required to report to Congress on (1) the differences among the definitions of certain lobbying-related terms found in LDA and the IRC, (2) the impact that any differences among these definitions may have on filing and reporting under the act, and (3) any changes to LDA or to the appropriate sections of the IRC that the Comptroller General may recommend to harmonize the definitions. As agreed with your offices, our objectives for this report were to describe the differences between the LDA and IRC section 4911 and 162(e) determine the impact that differences in the definitions may have on registration and reporting under LDA, including information on the number of organizations using each definition and the expenses they have reported; and identify and analyze options, including harmonizing the three definitions, that may better ensure that the public disclosure purposes of LDA are realized. To identify the differences among the LDA and IRC lobbying definitions, we reviewed the relevant statutory provisions. We also reviewed related regulations and guidance, including guidance issued by the Secretary of the Senate and the Clerk of the House of Representatives. We also reviewed journal articles and an analysis of the definitions of lobbying and met with registered lobbyists, representatives of nonprofit and business organizations, and other parties who were knowledgeable about the different statutory definitions and their effect on lobbying registrations. To determine the differences among the LDA and IRC lobbying definitions regarding the number of federal executive branch officials covered for contacts dealing with nonlegislative matters, we reviewed the LDA and IRC statutory definitions of covered executive branch officials that apply for lobbying contacts on nonlegislative matters. To determine the number of officials covered by these definitions, we counted the number of Executive Schedule Levels I through V positions listed in sections 5312 through 5316 of Title 5 of the United States Code. In several cases, these sections of Title 5 list federal boards and commissions as having Executive Schedule positions but do not specify the number of such positions. In these cases, we did not attempt to determine the number of positions and counted only one position for each such listed board or commission. Thus, our estimate of the number of Executive Schedule Levels I through V positions is understated. Further, to determine the number of officials covered, we obtained data from The United States Government Manual 1998/1999 on cabinet-level officials and the number of offices in the Executive Office of the President; the Department of Defense (DOD) on military personnel ranked 0-7 and above as of September 30, 1997; the U.S. Coast Guard, the Public Health Service, and the National Oceanic and Atmospheric Administration (NOAA) on the number of commissioned corps ranked 0-7 and above as of February 1999; the Office of Personnel Management’s (OPM) Central Personnel Data File on the number of Schedule C officials as of September 30, 1997; and Budget of the United States Government, Appendix, Fiscal Year 1999 on the actual full-time-equivalent employment for fiscal year 1997 in each office of the Executive Office of the President. To determine the impact that differences in the definitions may have on registration and reporting under LDA, we first had to define how we would measure impact. We defined impact as (1) the way differences among the definitions can affect who must register with the Secretary of the Senate and the Clerk of the House of Representatives and what lobbying expenses and related information must be included in those reports; (2) the number of organizations that reported using the LDA and IRC section 4911 and 162(e) definitions when reporting lobbying expenses and related information for July through December 1997; and (3) the lobbying expenses reported under each of the three definitions for this period. To determine the way differences among the definitions can affect who must register and what they must report, we reviewed, analyzed, and categorized the general effects of the differences that we found among the definitions under our first objective. We also looked for possible effects during our reviews of statutes, regulations, guidance, and journal articles. Finally, we discussed the possible effects of the differences among the definitions with registered lobbyists, representatives of nonprofit and business organizations, and other knowledgeable parties.