On April 5, 2018, the Bureau of Industry and Security (BIS) published in the Federal Register a final rule [Docket No. 160303184-8255-01] that amends the Export Administration Regulations (EAR) to impose a license requirement on exports and reexports of specified target assemblies and components for the production of tritium under new Export Control Classification Number (ECCN) 1A231, and for the related “production” technology for 1A231 commodities covered under ECCNs 1E001 and 1E201. The items identified in this rule are controlled for nuclear nonproliferation (NP) Column 1 and anti-terrorism (AT) Column 1 reasons. These new classifications are the result of a U.S. Government proposal submitted and agreed to by members of the relevant multilateral regime, the Nuclear Suppliers Group (NSG), in June 2017. This final rule, as required under the 0Y521 procedure and in fulfillment of multilateral commitments, implements the multilateral control for the items adopted by the NSG.