Natural gas imports require authorization from the Department of Energy (DOE) under the Natural Gas Act, in addition to standard CBP entry procedures. Pipeline gas and LNG are treated as distinct import modes, with LNG terminals also subject to FERC siting approval. These regulatory layers have no direct parallel in crude oil import procedures.

Establishments whose primary activity is extracting natural gas are classified under NAICS 21113 even if they perform some field processing. However, standalone gas processing plants that fractionate NGLs as their primary function are generally classified under NAICS 211130 or the relevant manufacturing code, depending on the scope of processing performed.