The Brief Congress hasn’t passed a funding bill or short-term extension to keep the government open. Why is the government shutting down? A government shutdown occurs when Congress fails to pass all 12 appropriations bills or a continuing resolution, which temporarily maintains funding while lawmakers finalize spending legislation. While the subsidies don’t expire until year’s end, congressional Democrats note that insurers are preparing to send out new rates Oct. 1. Lawmakers face a Wednesday midnight deadline to pass a short-term funding extension.