1. Short title This Act may be cited as the Untraceable Firearms Act of 2018 . 2. Requirement that all firearms be traceable (a) Definitions Section 921(a) of title 18, United States Code, is amended— (1) in paragraph (3)— (A) by inserting , including an unfinished frame or receiver after such weapon ; and (B) by striking or (D) any destructive device and inserting ; (D) any destructive device; or (E) any combination of parts designed or intended for use in converting any device into a firearm and from which a firearm may be readily assembled ; (2) in paragraph (10), by adding at the end the following: The term manufacturing firearms shall include assembling a functional firearm from a frame or receiver or molding, machining, or 3D printing a frame or receiver, and shall not include making or fitting special barrels, stocks, or trigger mechanisms to firearms. ; (3) by inserting after paragraph (29) the following: (30) The term frame or receiver — (A) means the part of a firearm that can provide the action or housing for the hammer, bolt, or breechblock and firing mechanism; (B) includes a frame or lower receiver blank, casting, or machined body that requires further machining or molding to be used as part of a functional firearm, and which is designed and intended to be used in the assembly of a functional firearm; and (C) does not include a piece of material that has had— (i) its size or external shape altered solely to facilitate transportation or storage; or (ii) solely its chemical composition altered. ; and (4) by adding at the end the following: (36) The term ghost gun — (A) means a firearm, including a frame or receiver, that lacks a unique serial number engraved or cast in metal or metal alloy on the frame or receiver by a licensed manufacturer or importer in accordance with this chapter; and (B) does not include a firearm that has been rendered permanently inoperable. . (b) Prohibition