Most federal departments and agencies have put out guidance about which programs will stay open and which ones won't if Congress doesn't pass a funding bill by the end of Tuesday.

The Social Security Administration (SSA) has revolutionized its digital access, mandating the use of Login.gov and ID.me for online services.

The U.S. Postal Service is not affected by a government shutdown as it does not rely on congressional funding. A government shutdown would halt services like environmental and food inspections, close national parks, and delay IRS functions.

US senators have failed to pass a last-minute funding bill to avert a government shutdown, all but guaranteeing funding will cut off at midnight That could bring some - but not all - US government services to a temporary halt President Donald Trump threatens mass ''irreversible" firings of federal workers if a shutdown happens Republican Senator John Thune says Republicans won't be "taken hostage",