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
Reid previously warned that any changes to the Senate's version by the House would result in at least the start of a government shutdown because of the time it would take to reconsider the proposal.
Republican Rep. Michael Grimm of New York said Saturday a "slight" shutdown could occur due to the little time left to pass a short-term spending plan for the new fiscal year that starts Tuesday.
"I'm hoping no, but just look at the timing," Grimm said, laying out a scenario in which the political wrangling leads to last-minute deliberations on Monday and beyond.
The prospect of a government shutdown caused by GOP tactics irked the longest serving member of Congress in history, Democratic Rep. John Dingell of Michigan, who said in a statement that "this once-deliberative body has been taken over by knaves and know-nothings, content with putting partisan politics ahead of the American people."
"I've said before that I believe that this current Congress would be incapable of passing the Ten Commandments or even the Lord's Prayer, and today's actions have only further galvanized that belief," said Dingell, who was first elected in 1955 and is serving his 30th term.
The legislative hot potato involving the spending plan began last week when the House stripped Obamacare funding from the proposal it sent to the Senate.
On Friday, the Senate voted on strict party lines to restore the Obamacare funding and send the measure back to the House.
That left Boehner with the choice of urging his divided Republican caucus to join Democrats in passing the Senate plan or to yield again to the tea party wing that seeks to undermine Obamacare.
Cruz loses filibuster bid
The Senate began its votes Friday by easily overcoming a filibuster led by GOP Sen. Ted Cruz of Texas against the spending plan. Cruz waged a 21-hour floor speech this week against Obamacare, but 25 more moderate Republicans rejected his tactics in voting with Democrats on Friday to move ahead on the measure.
Meanwhile, Democrats facing re-election next year in conservative-leaning states such as Mark Pryor of Arkansas, Mark Begich of Alaska, Mary Landrieu of Louisiana and Kay Hagan of North Carolina all resisted Republican pressure to buck their party over the Obamacare funding.
Responding to the GOP tactics, Obama said Friday that new exchanges for private health insurance under the reforms will open next week as scheduled -- even if there is a government shutdown.
"The House Republicans are so concerned with appeasing the tea party that they have threatened a government shutdown or worse unless I gut or repeal the Affordable Care Act," Obama said, adding: "That's not going to happen."
Democratic Sen. Barbara Mikulski of Maryland said the goal of the short-term spending measure was to provide time to work out a broader spending plan for the rest of fiscal 2014 that would ease the impact of forced cuts to the military and other government programs.
House GOP split