According to the Office of Personnel Management (OPM), the federal workforce is composed of an estimated 2.1 million civilian workers, and several federal agencies collect, compile, and publish statistics about this workforce. Source s may vary in their totals due to differences in how federal workforce statistics are compiled. Some sources rely on "head counts" of employees (OPM), some on total hours worked (such as the Office of Management and Budget [OMB]), some on surveys of employing agencies, and others on self-identification by workers surveyed in their homes. In addition, federal civilian employee databases may exclude particular departments, agencies, or branches of government. Some may also account for temporary or seasonal employees (such as those employed by the U.S. Census) depending on the time of year the statistics are generated. This report focuses on differences in methodologies, including exclusions, and the frequency of data collection employed by OMB and OPM to determine the size and scope of the federal workforce. These differences will facilitate the selection of appropriate data for specific purposes. One example of a key methodological distinction is the difference between "full-time equivalents" (FTEs) and on-board personnel. The following two examples illustrate how the FTE and on-board methods can be used to derive different federal workforce totals. Full-time equivalent employment is defined as the total number of regular straight-time hours (not including overtime or holiday hours) worked by employees divided by the number of compensable hours applicable to each fiscal year. Work years, or FTEs, are not employee "head counts." One work year, or one FTE, is equivalent to 2,080 hours of work. Table 1 offers examples in which there is a difference between the actual number of people and the number of FTEs working the same number of total hours. It also illustrates how measuring employment by hours can substantially change the perception of the number of employees it takes to accomplish the work. FTE employment numbers are used by OMB to manage employment in departments and agencies. The requirements for reporting FTE employment in the President's Budget are prescribed in Section 85 of OMB Circular No. A-11 on "Estimating Employment Levels and the Employment Summary (Schedule Q)." FTE data are published annually in OMB's the Budget of the United States Government under the individual department and agency accounts in the Appendix as well as in the Analytical Perspectives and Historical Tables volumes. OPM defines on-board employment as the number of employees in pay status at the end of the quarter. Data for on-board employment provide employee "head count" in most departments and agencies as of a particular date, including full-time, part-time, and seasonal employees. OPM's Employment and Trends report and OPM's FedScope database provide on-board employment headcounts. When calculating on-board personnel, the number of full-time, part-time, and seasonal workers at an agency is relevant. For example, an agency reporting 10 FTEs could conceivably report 20 "on-board" employees, depending on employees' work schedules. In addition, the "on-board" headcount may result in wide variances in employment numbers, depending on the specific date the employees are counted. For example, the Census Bureau hires 7,000 Census enumerators every 10 years. The federal on-board employees count is likely to be larger during the duration of their employment. OPM is an independent agency that functions as the central human resources department of the executive branch. In fulfilling its mission, OPM collects, maintains, and publishes data on a large portion of the federal civilian workforce. In FY2010, OPM established a system called the Enterprise Human Resources Integration-Statistical Data Mart (EHRI-SDM). This automated system provides access to personnel data for 96% of nonpostal federal civilian executive branch employees. The database does have exclusions; for example, not all executive branch agencies submit their personnel data to OPM. These exclusions include some national security and intelligence agencies, and the Postal Service. Even with these exclusions, the EHRI-SDM is widely regarded as the most comprehensive resource available on the size and scope of the federal workforce. More than 100 data elements are collected for each federal employee within the EHRI-SDM. These data are aggregated by OPM and published in the resources described below. FedScope is a website that provides public access to the EHRI-SDM, covering the most recent five years of employment, accession, and separation data provided by approximately 120 federal agencies. It is available at http://www.fedscope.opm.gov/ . FedScope data are presented in five subject categories, called "cubes," each covering a different subject and time span. The following are descriptions of the data cubes available through FedScope: Employment . This set of cubes contains the total number of federal employees of the included agencies, as well as other information such as age, gender, length of service, occupation, occupation category, pay grade, salary level, type of appointment, work schedule, agency, and location. Data are published quarterly (March, June, September, and December) for the most recent eight fiscal years. September data, which align with the end of the fiscal year, are available from 1998 to the present. Accession . This set of cubes contains the number of people added to the federal civilian workforce each fiscal year. It includes data elements on employees hired from outside the government and those who transferred from one type of federal service category to another. The most recent 14 fiscal years of data are available. Separation . This set of cubes contains the number of people who leave the federal civilian workforce each fiscal year. It captures data elements on employees who transferred to other agencies, voluntarily resigned, retired, experienced a reduction-in-force (RIF), were terminated, or died while employed. The most recent 14 years of data are available. Employment Trends . This set of cubes displays the most recent five years of employment cube data together in one interface, facilitating workforce data comparisons and trend recognition. Diversity . This set of cubes sorts data by an Ethnicity and Race Indicator. Data elements for 13 categories of racial and ethnic groups are available for the most recent eight years. September data, which align with the end of the fiscal year, are available from 2006 to the present. Table 2 provides some of the most commonly requested data available from FedScope. Employment and Trends is an occasional publication from OPM based on on-board employee data. It provides data on executive departments and independent agencies, including the Department of Defense (DOD) civilian employees, Executive Office of the President, legislative branch, and judicial branch. It presents selected data in detailed statistical tables and includes information by government branch, agency, and location. Introductory material in Employment and Trends explains the data presented, time lags in data releases, and caveats to consider when calculating workforce totals. The most recently released version of this resource is available at http://www.opm.gov/policy-data-oversight/data-analysis-documentation/federal-employment-reports/#url=Employment-Trends . Common Characteristics of Government is an annual publication that includes a brief outline of OPM's federal employee databases and it includes frequently requested data. The latest edition (FY2017) is available at https://www.opm.gov/policy-data-oversight/data-analysis-documentation/federal-employment-reports/common-characteristics-of-the-government/ccog2017.pdf . Sizing Up the Executive Branch of the Federal Workforce is an OPM report that provides access to frequently requested data related to the executive branch. This report includes some information related to the size of the executive branch by month and year, types of employment, and other frequently requested data. The most recent report (FY2017) is available at https://www.opm.gov/policy-data-oversight/data-analysis-documentation/federal-employment-reports/reports-publications/sizing-up-the-executive-branch-2016.pdf . OMB is the largest component of the Executive Office of the President. OMB reports directly to the President, and it assists executive departments and agencies in implementing priorities and commitments of the President. OMB produces the Budget of the United States , which includes federal employee statistics created using the FTE counting method. The Budget of the United States , sometimes referred to as the President's Budget, is a four-volume set of documents that includes detailed financial information on individual programs and appropriations accounts. Three volumes of the budget include information on direct civilian FTEs. Tables in the President's Budget typically include actual FTE levels for prior fiscal years and estimates for the two most current fiscal years. The U.S. Government Publishing Office website posts budget volumes dating back to FY1996 at https://www.govinfo.gov/app/collection/BUDGET/ . Table 3 illustrates an example of some commonly requested federal employment data found within the President's Budget. The following volumes of the President's Budget include information on federal employees. The current volumes can be accessed at https://www.whitehouse.gov/omb/budget . The Analytical Perspectives volume typically includes information on the federal workforce, sometimes including information on occupations, trends, education level, age distribution, and other factors. The most current Analytical Perspectives volume of the President's Budget is available at http://www.whitehouse.gov/omb/analytical-perspectives/ . The Appendix volume typically includes an estimate of individual agency FTEs based on the President's proposal along with an estimate and actual FTE count for the prior two years. The most recent Appendix volume of the President's Budget is available at http://www.whitehouse.gov/omb/appendix . The Historical Tables volume of the President's Budget includes historical data on topics such as budget, receipts, outlays, and deficits. This volume also typically includes historical employment counts. The most recent Historical Tables volume of the President's Budget is available at http://www.whitehouse.gov/omb/historical-tables . The resources described in this report contain data often requested by Members or congressional staff. The sources covered differ in the methodology, including exclusions, and the frequency of data collection. Users should be aware of these differences when using federal workforce statistics from these sources.

Summary: This report describes online tools, reports, and data compilations created by the Office of Management and Budget (OMB) and the Office of Personnel Management (OPM) that contain statistics about federal employees and the federal workforce. The report also describes key characteristics of each resource and briefly discusses selected methodological differences, with the intention of facilitating the selection of appropriate data for specific purposes. This report is not intended to be a definitive list of all information on the federal workforce. It describes significant and recurring products that contain specific data often requested by Members or congressional staff.