The Standard Occupational Classification Systems

The Standard Occupational Classification System (SOC) was devised in 1977, and revised and reissued in 1980, to link occupational data collected through different systems to a single standard system. Despite agreements to maintain and update the original system, the original system was not revised after 1980 until the Office of Management and Budget chartered the SOC Committee in 1994. In 1998 OMB issued the revised SOC. In the 1998 SOC, there are four levels of aggregation: 1) major group; 2) minor group; 3) broad occupation; and 4) detailed occupation. Each level in this hierarchy is designated by a six-digit code. The first two digits of the 1998 SOC code represent the major group; the third digit represents the minor group; the fourth and fifth digits represent the broad occupation; and the sixth digit represents the detailed occupation. Major group codes end with 0000 (e.g., 19-0000 Life, Physical, and Social Science Occupations), minor groups end with 000 (e.g., 19-1000 Life Scientists), broad occupations end with 0 (e.g., 19-1010 Agricultural and Food Scientists), and detailed occupations end with a nonzero digit (e.g., 19-1011 Animal Scientists).