S. 4373 would amend the National Emergencies Act to limit the duration of national emergencies declared by the President to 30 days unless the Congress subsequently approves or extends the declaration. The bill also would require the President to report to the Congress periodically on the need for and status of declared emergencies. CBO cannot predict the number or timing of future declarations but expects that most would be approved by the Congress. Under S. 4373 emergency declarations could have a shorter duration than under current law. If that happens, direct spending related to such emergencies would decline; however, because CBO expects that the Congress would approve most declarations, we estimate that any reduction in direct spending would be insignificant. S. 4373 also would extend protections to U.S. persons who may face sanctions for contributing to a national emergency declared under the International Emergency Economic Powers Act. If enacting the protections in S. 4373 leads the Administration to impose fewer sanctions, revenues from sanctions penalties, and direct spending of those penalties, would decline. CBO estimates that any reduction in direct spending or revenues would be insignificant. CBO has not estimated the bill’s effects on spending subject to appropriation. The bill contains no intergovernmental or private-sector mandates as defined in the Unfunded Mandates Reform Act.