The House early Sunday adopted a Republican-backed plan to wipe out the tax on medical devices as part of its plan to avert a government shutdown.
The vote was 248-174, mostly along party lines.
The House immediately began voting on a second amendment to delay the Affordable Care Act for a year.
It was part of the House debate on Republican-backed amendments to continuing a standoff that threatens to force a government shutdown.
Passage of the amendments, expected later Saturday night, would send a temporary budget resolution back to the Senate, where Democrats vow to again block the anti-Affordable Care Act amendments.
President Barack Obama has added a veto threat to that position.
Without a deal, a government shutdown will begin at 12:01 a.m. Tuesday.
A Senate Democratic source told CNN there were no plans to convene the Senate before Monday, when the current fiscal year ends.
The decision to vote on the House amendments Saturday night emerged from a rare weekend GOP caucus meeting called by House Speaker John Boehner.
Senate Majority Leader Harry Reid called the Republican strategy "pointless" and said the Democratic-led Senate would reject the GOP alternatives, while the White House said Obama would veto the House proposal if it reached his desk.
A separate White House statement said voting for the GOP measure "is voting for a shutdown."
The partisan back-forth over the spending plan -- called a continuing resolution in legislative jargon -- came after the Senate on Friday restored funding for the Affordable Care Act that House Republicans stripped from their original version and sent the proposal back to the House.
Boehner convened his caucus on Saturday to forge a counteroffer to the Senate changes that restored funding for Obama's signature health care reforms that are despised by the GOP's tea party conservative wing in Congress.
A statement by Boehner and other House GOP leaders said Saturday's votes would be on "two amendments to the Senate-passed continuing resolution that will keep the government open and stop as much of the president's health care law as possible."
One amendment would delay full implementation of the Affordable Care Act for a year, and another "permanently repeals" the medical device tax that the statement said was "sending jobs overseas."
The amendments also would fund the government until December 15, a month longer than the Senate version.
Military pay in a shutdown
Showing that the House Republicans don't expect the Senate to accept their changes, the leaders' statement said a separate vote Saturday would ensure that the military gets paid in the event of a government shutdown.
Officials estimate the military pay could be affected by a shutdown as soon as Oct. 14, and the GOP move was considered a political gesture to shield the party from criticism that its brinksmanship could hurt U.S. fighting forces.
In further evidence of the political nature of the separate military pay proposal, Democratic Rep. Chris Van Hollen of Maryland said Democrats would likely support it.
On the spending plan, though, Reid said the Republican tactics amounted to what he described as extortion by "tea party anarchists."
"To be absolutely clear, the Senate will reject both the one-year delay of the Affordable Care Act and the repeal of the medical device tax," Reid said in a statement. "After weeks of futile political games from Republicans, we are still at square one."
Meanwhile, the White House made clear on Saturday that Obama dismisses any effort to tie provisions undermining the Affordable Care Act to the spending measure needed to prevent a government shutdown.
"Republicans have tried and failed to defund or delay the health care law more than 40 times, and they know this demand is reckless and irresponsible," said the statement from White House spokesman Jay Carney, adding that Obama would not negotiate on the Affordable Care Act or spending issues "under threats of a government shutdown that will hurt our economy."
Shutdown deadline looms