How BLS defines an occupation: the SOC

Every occupation on this site has a code such as 29-1141. The code comes from the Standard Occupational Classification, the federal system that every statistical agency uses to sort jobs, and it determines what counts as “registered nurses” when BLS reports their wages.

The structure

The 2018 SOC, the current version, is a four-level hierarchy. At the top are 23 major groups, identified by the first two digits: 29 is healthcare practitioners and technical occupations, 15 is computer and mathematical occupations, 53 is transportation and material moving. Below them are 98 minor groups, then 459 broad occupations, then 867 detailed occupations. A detailed occupation code ends in a nonzero digit; a broad occupation ends in 0; a minor group ends in 00; a major group ends in 0000.

The system is maintained by the Office of Management and Budget through a committee of agencies and is revised about every ten years. The previous revision was in 2010.

How a job is assigned

The SOC classifies jobs by the work performed, not by the worker’s education, industry or job title. The user guide gives the rules: a worker is classified in the occupation that takes most of their time; a supervisor who spends most of their time supervising is a supervisor, not a member of the supervised occupation; and a worker who could fit several codes goes to the one with the highest skill requirement. Titles matter only as hints. “Analyst” on a business card can map to a dozen codes.

In the OEWS survey the assignment is made by the employer who answers the questionnaire, using the descriptions BLS supplies. That is a source of error BLS edits for but cannot eliminate: two employers can place the same job in different codes.

Why the site has about 830, not 867

BLS publishes OEWS wages for about 830 detailed occupations. The difference arises because some detailed codes are too small to estimate separately and are combined into their broad occupation, which then appears in the data at both levels with identical figures. This site keeps such a combined entry once, under the broad code, and says so on the page. A few occupations also exist in the SOC but have no wage and salary employment to speak of, because the work is done almost entirely by the self-employed, whom OEWS does not cover.

Residual codes

Every broad occupation that does not account for all its minor group’s workers has an “all other” code ending in 9, such as 15-1299, computer occupations, all other. These collect jobs that fit the group but no listed detailed occupation. Their wages are real estimates for a real set of workers, but the set is heterogeneous by design, and the percentile spread on such pages is usually wide.

Reading codes on this site

Occupation pages show the SOC code as a data field and group related occupations by their broad code, which is how the “related occupations” list is built; the state tables use the same codes, so a row can be followed from the national page to any state. The 22 major-group hubs follow the SOC major groups (the 23rd, military-specific occupations, has no OEWS data). The occupations hub lists every detailed occupation that passed the publish gate, and finding your SOC code explains how to locate a job in the system when its title does not match.

Two neighbors to be aware of: the Census Bureau and the Occupational Outlook Handbook both use occupation lists derived from the SOC but not identical to it. The handbook groups several SOC codes into one profile; see what the OOH is. When a figure here and a figure elsewhere disagree, the first thing to check is whether they are describing the same code.

The classification is a measurement instrument. Its boundaries are conventions, and the number on a page describes everyone an employer put inside the boundary, no more and no less.