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1. What are industry, occupation, and class of worker, and why are they important?
2. Where can I obtain industry, occupation, and class of worker data?
3. Are there any industry, occupation, and class of worker Census products with other demographic, social, and economic characteristics?
4. If the data that I need are not available, can I request a custom tabulation for industry, occupation, and/or class of worker?
5. What are the classification systems for industry and occupation?
6. How do I compare occupation data across time?
7. How do I compare industry and occupation data from different years if the classification systems have changed?
8. When was the last time that the industry, occupation, and class of worker items on the ACS questionnaire were updated?
9. Is there a complete list of industry descriptions and occupation titles available for public use?
10. What is the industry and occupation coding process?
11. How are the industry, occupation, and class of worker codes aggregated?
12. Where can I find detailed data to use when creating my affirmative action plans?

Industry is the description of the kind of business of the respondent’s employer. Occupation is the kind of work a person does at their job. Class of worker categorizes people according to the type of ownership of the employing organization. These data are relevant to a wide range of uses. For more information on the definitions of these measures and their applications, see the About page.

The primary source of these data since 2005 is the American Community Survey (ACS), an annual, nationally-representative survey that replaces the decennial census long form. They are also collected on other surveys, such as the Current Population Survey (CPS), the Survey of Income and Program Participation (SIPP), the decennial census of the Island Areas, and on older decennial censuses. Most of these sources are available online; see the Data page.

Yes, the Census Bureau publishes data products that tabulate these data with several other measures, including age, sex, race, and median earnings. There are also Public Use Microdata Samples (PUMS) for ACS with which users can create their own tabulations. Most of the industry and occupation data for ACS can be obtained from data.census.gov. For data links, a list of ACS tables, and other information, see the Data page.

Yes, though users are advised to explore the possibilities of creating their own tabulations using the Public Use Microdata Sample (PUMS) first. The PUMS code list which is revised form of the detailed code list. The PUMS code list follows data disclosure avoidance rules put forth by Census Bureau’s Disclosure Review Board (DRB). There must be 10,000 weighted observations nationally in each industry code and occupation code; otherwise, the code is combined with another similar code. If your data needs cannot be met with the PUMS, you can request a custom tabulation on the ACS website. Census Bureau staff will contact you within 3-5 business days after you submit the request form to discuss your request before starting work. The minimum cost of a custom tabulation is $3000 (and it is often much more). The minimum timeframe is 8 weeks (and it is often much longer, especially during the summer and fall). The DRB must review and approve all requests before work is started. View the Census Bureau Statistical Safeguards for more information.

There are two standard classifications that are used throughout the federal government: the North American Industry Classification System (NAICS) and the Standard Occupational Classification (SOC) system, which are regularly updated to account for changes in the structure of the economy and in the needs of data users. Both systems are adapted by the Census Bureau to create the Census codes and categories that appear in our microdata and published data products.

The NAICS, which is the basis of the Census Industry Code List, was developed by the United States, Canada, and Mexico to provide comparable industry statistics across the three countries, and it replaced the Standard Industrial Classification (SIC) as the federal standard in 1997. It is a comprehensive system covering the entire field of economic activities. Detailed information about the structure of the most recent, the 2022 NAICS, can be found on the Census NAICS page.

The SOC, which is the basis of the Census Occupation Code List, is the federal government’s own regularly updated system for classifying occupations, which are grouped according to the nature of the work performed. This system provides a mechanism for cross-referencing and aggregating occupation-related data collected by social and economic statistical reporting programs. Information on the structure and definitions of the most recent update, the 2018 SOC, can be found on the BLS SOC page.

The old SOC was made up of 22 divisions organized into a 4-digit hierarchical structure. The 2000 SOC systems use a 6-digit structure for its occupational categories, divided into 23 major groups which are sometimes called "job families." The general concept behind "job families" is to put all people who work together into the same group regardless of their skill level. So, for example, in the 2000 SOC doctors, nurses, and health technicians are all in the same group instead of in different groups. Similarly, first-line supervisors are in the same groups as the workers they supervise, and helpers are in the same groups as the workers they help. See Revising the Standard Occupational Classification System for more information on the transition from the 1980 to the 2000 system.

The changes from the 2000 to 2010 SOC were much more modest, with the 2010 version following the same basic hierarchical structure as the 2000 SOC. Most changes were modifications of individual categories to reflect changes in occupational structure and to incorporate requests of data users. In addition, a new set of detailed coding guidelines was added to supplement the broader classification principles. For more information on this revision, please see Revising the Standard Occupational Classification system for 2010.

The SOC was again updated in 2018 based on comments from the public and from federal agencies on the proposed revision of the 2010 SOC Classification Principles. The intention was to retain the 2010 SOC Coding Guidelines and Major Group Structure; and for the correction, change, or combination of selected 2010 SOC detailed occupations, and inclusion of new detailed occupations. The 2018 SOC was published on November 28, 2017. In it, workers are classified into one of 867 detailed occupations according to their occupational definition. To facilitate classification, detailed occupations are combined to form 459 broad occupations, 98 minor groups, and 23 major groups. For more information on this revision, see the 2018 SOC Revision Process section.

The federal government’s official classifications (NAICS and SOC, see above) are regularly updated and the Census Bureau always uses the most recent editions in developing its industry and occupation coding system. To aid data users in making comparisons across time, crosswalks with conversion rates have been developed. Conversion rates allow data users to compare occupation data from years that use the previous code list to data from years that use the latest code list.

For an explanation of industry and occupation codes changes between 1990 and 2000, see The Relationship Between the 1990 Census and Census 2000 Industry and Occupation Classification Systems, Technical Paper 65.

For occupation crosswalks between 2000 and 2010, see 2006-2010 ACS PUMS Occupation Conversion Rates (2002 to 2010 Occupation Census codes)

For an explanation of industry and occupation codes changes between the 2010 and 2018 occupational classification, see Recent Changes in the Census Industry and Occupation Classification Systems, Technical Paper 78.

One of the issues that affect the comparability of industry, occupation, and class of worker data across time is changes in a questionnaire. In 2016, ACS underwent content testing for the class of worker, industry, and occupation questions. As a result, in 2019, the ACS implemented changes to the formatting, numbering of questions, and examples for the industry and occupation write-in questions provided on the questionnaire. Also, ACS adopted an additional response category of “Active Duty or U.S. Armed Forces or Commissioned Corps” in the Class of Worker question to aide coders in assigning the best industry code for military cases. Other changes were implemented to the formatting and numbering of questions. For information on the changes to the industry and occupation questionnaire items, see the 2016 American Community Survey Content Test: Industry and Occupation. For information on the changes to the class of worker questionnaire item, see 2016 American Community Survey Content Test: Class of Worker.

Yes, the Alphabetical Indexes of Industries and Occupations, which are used by the Census Bureau to code industry and occupation responses. The indexes are comprehensive lists of specific industries and occupations developed over time and continuously updated through review of census and survey responses, and industry and occupation classification changes. These are primarily used in classifying a respondent's industry (employer's type of business) and occupation (employee's type of work) as reported in demographic surveys conducted by the Census Bureau. Coders convert the written questionnaire occupations and industry descriptions to 4-digit numeric codes by comparing these descriptions to entries in the indexes. These list over 23,000 industry and 33,000 occupation titles in alphabetical order. These are available in the Guidance for Industry and Occupation Data Users page.

Coding industry and occupation data for the American Community Survey (ACS) is a massive operation. Every year over 2 million industry and occupation write-ins are assigned Census I&O codes. To convert subjective responses into quantitative data, the Census Bureau has developed a complex coding process over nearly two centuries. The main components of this process are the Alphabetical Indexes of Industry and Occupation, the Census Military Index, the Employer Name List (ENL), a staff of clerical coders, and more recently, the ACS Industry and Occupation Autocoder (“the autocoder”) and its accompanying dictionaries and hardcodes. During processing, the objective is to assign the “best codes” for industry and for occupation, given the write-in responses to each as well as the respondent’s class of work, geographic location, active duty military status, and demographic descriptive characteristics (e.g., age, sex, educational attainment). First, the industry and occupation write-in data from each of the collection modes are combined. Next, the cases are processed through the autocoder. The autocoder is a set of logistic regression models, dictionaries, and consistency edits (“hardcodes”). If the autocoder fails to assign both an industry code and an occupation code to a case, then the case is sent to the National Processing Center (NPC) in Jeffersonville, Indiana. At NPC, a dedicated staff of industry and occupation clerical coders assign the “best codes” to the remaining cases using the Alphabetical Indexes of Industry and Occupation, the Census Military Index, the ENL, and the Industry and Occupation (I&O) Coding Procedures. For more information, see Recent Changes in the Census Industry and Occupation Classification Systems, Technical Paper 78.

Cases are coded according to the most detailed level of the relevant classification system possible (accounting for factors such as disclosure concerns for small occupations), but the estimates are collected at various levels of aggregation for published data products. For industry and occupation, these levels parallel the hierarchy of the NAICS and SOC themselves, which include designated optional categories for aggregation above the level of sectors (NAICS) and major groups (SOC).

The Census Bureau currently uses nine basic classifications for class of worker: private for-profit and private not-for-profit; local, state, and federal government, and active duty U.S. Armed Forces or Commissioned Corps (for government workers); self-employed not incorporated and self-employed incorporated (for self-employed); and unpaid family workers. These basic categories are sometimes aggregated for different publications and purposes. For class of worker data, there are up to four levels of aggregation available depending on the categories, and estimates are reported in multiple combinations. For example, "Government workers" might be reported collectively, or separately for federal, active duty U.S. Armed Forces or Commissioned Corps, and state and local. “Private-for-profit wage and salary workers” includes employee of private company workers and self-employed in own incorporated business workers. For details, see the About Class of Worker page.

The Census Bureau produces a custom tabulation called the Equal Employment Opportunity Tabulation (EEO Tab) that presents detailed occupational data crossed by several demographic and social characteristics, including for all geographies. The most recent EEO File was produced with data from ACS 2014-2018 5-year data. The tabulation and associated documentation, such as technical documentation, are available through a dedicated EEO Tabulation topic page, which includes an online data tool. Please note that the Census Bureau is not responsible for, and cannot assist with, reporting to federal agencies to support the enforcement of employment discrimination laws and regulations. For contact information regarding reporting, see the Frequently Asked Question (FAQ’s) on the EEO Tabulation topic page.