2012 NAICS codes 212231, Lead Ore and Zinc Ore Mining, and 212234, Copper Ore and Nickel Ore Mining, were collapsed into a new 6-digit industry: 212230, Copper, Nickel, Lead, and Zinc Mining. Sector 21, Mining, Quarrying, and Oil and Gas Extraction - Industries in Subsector 211, Oil and Gas Extraction, were restructured, resulting in two new 6-digit industries: 211120, Crude Petroleum Extraction and 211130, Natural Gas Extraction. Noticeable changes were made to six of the 20 NAICS sectors during the 2017 revision of NAICS.
These included the addition of new and emerging industries, content revisions for selected areas, title changes, and clarification of a few industry definitions.
For 2017, revisions were made to address changes in the economy.
