To require the Congressional Budget Office to conduct an economic review of the economic impact of tariff modifications before implementation.

HR 4326 requires the Congressional Budget Office (CBO) to conduct an economic review of any proposed change to import tariffs or duties before it takes effect. Specifically, no modification to an existing tariff rate can go into effect until the CBO publishes its review of the expected economic impact on a public website. This applies to all tariff changes relative to rates in effect before the bill's enactment date. The bill directly affects the process for implementing new or modified import duties by adding a mandatory review step before implementation.