From ABC News.

Both Republican and Democratic proposals that would have funded the government past Tuesday failed in the Senate during the eleventh hour, effectively shutting down the government at 12:01 a.m. on Wednesday.

The federal government ran out of money after a Democratic-backed spending bill that would have extended health care subsidies under the Affordable Care Act and reversed cuts to Medicaid failed, as well as the GOP-backed stopgap funding measure that would have funded the government for seven weeks also failed.