evidence: A shutdown occurs when Congress fails to approve new spending for federal agencies, which are generally barred from spending money without congressional authorization. There are some exceptions, like activities needed to protect life and property. Each agency makes its own determination about which employees are needed to stay on the job, meaning the impact on federal operations can vary widely. [...] Because of money Democrats approved through their landmark healthcare, tax and climate legislation last year, normal operations at the IRS would continue, and the agency's 83,000 workers would be saved from furlough. Taxpayers are still required to pay taxes during a shutdown. The tax agency's circumstances under a possible government shutdown this year would differ greatly from years past. In 2018, at least 26,000 furloughed IRS workers were called back to work without pay to get ready for the tax season, though 14,000 of those recalled employees didn't return, with thousands seeking permission under their union contract to be absent because of financial hardship.