358.10 Uses Permitted.
(A) Exposed and Concealed. The use of EMT shall be
permitted for both exposed and concealed work.
(B) Corrosion Protection. Ferrous or nonferrous EMT, elbows,
couplings, and fittings shall be permitted to be installed
in concrete, in direct contact with the earth, or in areas
subject to severe corrosive influences where protected by corrosion
protection and approved as suitable for the condition.
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.