Will the U.S. government shut down in December 2026, when the current stopgap expires?

Both parties spent the fall proving they did not want a shutdown on the ballot. Senate Democrats, who withheld votes twice in fiscal 2026, voted for a stopgap that gave them only modest wins, and Speaker Mike Johnson sold the September bill as avoiding 'another Democratic shutdown.' After November 3 that electoral fear disappears, but a new one replaces it: nobody wants to own a Christmas shutdown, and the members who lost their seats have little reason to fight for anything but a quick exit.

The pressure point is what the winners want. House Appropriations Chair Tom Cole said on the record that everybody's calculations will change after the election. A party that just won a chamber has an incentive to punt full-year bills into January, when it has more power. A punt is a stopgap, not a shutdown. The real risk is a principal who needs a visible win before the year ends: in 2018 the lame-duck lapse came when the President refused a stopgap to press for border wall money, after his party lost the House.

Democrats have learned that shutdowns did not pay. NPR's account of the two record shutdowns this Congress is blunt: Democrats did not extract concrete concessions. That lowers the chance they start one in December. The remaining triggers sit on the other side of the table: the White House's push for a far larger defense budget and for more immigration enforcement money.

Reference class: lame-duck funding deadlines, meaning a stopgap that expires between Election Day and the end of the year. Since 1980 we count 13 of them (1980, 1982, 2000, 2002, 2004, 2006, 2010, 2014, 2016, 2018, 2020, 2022 and 2024). Two ended in a funding gap: December 1982 and December 2018. That is roughly 15 percent. In every other case Congress passed another stopgap or an omnibus, sometimes with hours to spare, as in December 2024.

Closest analogue: December 2018. A Republican trifecta had just lost the House, a stopgap expired in mid December, and the President refused to sign a bill without wall money, producing a 35-day partial shutdown. Where it breaks: in 2018 the dispute was a single, symbolic demand the President had campaigned on. In 2026 the biggest ask, a $1.5 trillion defense budget, is partly being routed through a separate $350 billion reconciliation request that does not need Democratic votes, which takes some of the pressure off the appropriations bill.

Where the reference class understates the risk: this Congress is an outlier. It produced a 43-day shutdown in October 2025, a brief partial lapse from January 31 to February 3, 2026, and a 76-day Homeland Security shutdown that ended April 30. Three lapses in one fiscal year is without modern precedent.

Start from the lame-duck base rate of about 15 percent (2 of 13 since 1980).

Adjust up 10 points for this Congress's demonstrated willingness to let funding lapse (three lapses in fiscal 2026 alone). Adjust up 4 points for an unusually wide topline gap: Republicans want a large defense increase with non-defense cuts, and Democrats demand parity. Adjust down 5 points because the exit is cheap and proven: the September stopgap passed the Senate 90 to 6 and the House 370 to 48, and both appropriations leaders, Cole and Rosa DeLauro, are on record wanting to finish the year without drama.

15 + 10 + 4 minus 5 lands at 24 percent, with an honest band of 15 to 35 percent. Kalshi's contract on a shutdown on December 12 trades near 29 percent; we sit a little lower because we weight the cheap short-stopgap exit more heavily than the market does.