The closure follows the Senate’s failure to secure enough votes to pass a temporary budget bill that would have kept federal agencies funded through November 21. The White House blamed Democrats for blocking the measure, which included a spending request of up to 1 trillion USD. Republicans had put forward a temporary bill to extend funding, but Democrats insisted the bill also address health care. Specifically, Democrats want to reverse Medicaid cuts included in President Donald Trump's major summer bill and extend tax credits that help millions of Americans pay for health insurance through the marketplaces established by the Affordable Care Act.

Without new funding, federal agencies must suspend operations and place non-essential employees on leave. During the record-breaking 35-day shutdown in 2018-2019, about 340,000 of 800,000 federal workers were furloughed. The rest continued to work under exemptions.