A look at the legislative twists and turns in Congress' battle over the partial government shutdown and the entwined Republican effort to curtail President Barack Obama's health care law:
Sept. 20: With a potential government shutdown 11 days off, the Republican-run House ignores a White House veto threat and uses a near party-line 230-189 vote to approve legislation denying money for much of the health care law while keeping the government open through Dec. 15. The measure moves to the Democratic-led Senate.
Sept. 24-25: As the Senate debates legislation to keep the government open, tea party Sen. Ted Cruz, R-Texas, and other conservatives speak on the chamber's floor for more than 21 consecutive hours against the health care law often called Obamacare. They do not delay or prevent votes, but they help intensify conservative fervor for using the shutdown bill to try forcing Democrats to limit Obamacare.
Sept. 27: The Senate votes 79-19 to end conservative efforts to derail the bill preventing a shutdown, with all Democrats and most Republicans opposing the conservatives. The Senate uses a party-line 54-44 vote to remove the House-approved provision defunding Obamacare, and an identical 54-44 vote to approve the overall bill. The bill, financing agencies through Nov. 15, goes back to the House.
Sept. 29: Just after midnight on Sunday morning, the House uses a rare and lengthy weekend session to shift its demands for restricting Obamacare. By a near party-line 231-192 vote, the House votes to delay implementation of the health care law by a year. It also votes 248-174 to repeal a tax on many medical devices that helps pay for the health care overhaul. The votes send the revamped shutdown bill back to the Senate.
—2:20 p.m. EDT: By 54-46, the Senate removes the House provisions postponing Obamacare and erasing the medical device tax. The shutdown bill moves back to the House.
—8:41 p.m.: The House approves a new shutdown bill 228-201 with different demands on Obamacare. It would delay for a year the requirement that individuals purchase health insurance, and require members of Congress and their staff to pay the full cost of health insurance, without the government paying part of the costs. The measure bounces to the Senate.
—9:37 p.m.: The Senate votes 54-46 to strip the House provisions on individual health insurance and federal health coverage subsidies for lawmakers and staff. The bill returns to the House.
—Shortly before midnight: White House Budget Office Director Sylvia Mathews Burwell sends memo to agency heads stating that a shutdown seems unavoidable and telling them to implement their plans for winding down.
—12:01 a.m. EDT: Government's new fiscal year begins. With no spending legislation enacted, partial federal shutdown begins to take effect.
—1:11 a.m.: House votes 228-199 to stand by its language delaying required individual health coverage and blocking federal subsidies for health insurance for lawmakers and staff, and to request formal negotiations with the Senate.
—8 a.m.: Federal health care exchanges open.
—10 a.m.: Senate votes 54-46 to reject House effort for formal bargaining.
—8:02 p.m.: Republicans stage votes aimed at selectively ending parts of the shutdown. But the chamber rejects each of three bills after the GOP uses an expedited procedure that requires two-thirds majorities for passage. The House votes 264-164 to fund veterans' benefits; 265-161 to let District of Columbia's municipal government spend locally raised funds; and 252-176 to reopen national parks and museums along the National Mall. All three lose.
Oct. 2: Using rules that merely require a simple majority for passage, Republicans push the parks measure through the House by 252-173, a bill reopening the National Institutes of Health by 254-171, and by voice vote a bill letting the District of Columbia municipal government spend funds it raises. Obama summons the top four congressional leaders to the White House to discuss the impasse, but participants report no progress.
Oct. 3: Continuing their strategy of daring Democrats to oppose restarting popular programs, Republicans push a bill through the House, 265-160, for paying members of the National Guard and Reserves. The House approves another bill financing veterans' programs by 259-157. Democrats have said such targeted bills will die in the Senate.