National parks and memorials have reopened, and hundreds of thousands of federal workers headed back to work Thursday following the end of a 16-day partial government shutdown. Lawmakers are now facing the next potential standoff over long-term budget negotiations, with a deadline of December 13 for the Budget Committee to report back to their House and Senate colleagues on a potential deal. Committee leaders include Republican Congressmember Paul Ryan of Wisconsin, who has pushed for gutting Medicare and Medicaid. Another budget landmark comes in mid-January when the next round of across-the-board spending cuts known as sequestration are due to kick in.