The HCPCS miscellaneous code for unclassified drugs, used when no permanent J-code exists.
J3490 carries no price and no unit definition, so the payer cannot adjudicate it from the code alone. Claims must carry the 11-digit NDC, the quantity administered with a unit qualifier, the drug name and strength, and usually the acquisition invoice.
Because pricing is manual, J3490 claims are slower to pay and far more likely to be returned as unprocessable. Check every quarter whether the drug has received a permanent code.