The House approved H.R. 2576, 262-157, with the help of 26 Democrats and the support of the Obama administration, The Hill reported.
The Congressional Budget Office has said as many as 1 million people could be affected by the restrictions, which, among other things, would include Social Security benefits as income in determining eligibility.
"By aligning this definition with other federal subsidy programs, the legislation ensures that taxpayer funds will not be used to enroll middle-class individuals into Medicaid, which is an abuse of the program's mission to provide targeted assistance to those who are most in need of help," said Ways and Means Committee Chairman Dave Camp, R-Mich.
Some Democrats protested.
"This provision was not a glitch," said Rep. Joseph Crowley, D-N.Y. "It was written into the law deliberately, and anyone who would have read the bill would have known that. I don't care if the president is going to sign this bill. It doesn't make it right."
Meanwhile, Republicans said Thursday last year's healthcare overhaul hurts married couples by making it harder for them to get insurance subsidies.
A report from House Oversight Committee Chairman Darrell Issa, R-Calif., obtained by The Hill, says married couples will receive 14 percent of the tax credits under the law, while more than 7 million singles will see their tax burden eliminated.
"While the intent of [healthcare reform] was probably not to penalize marriage and take millions of people off the tax rolls, it will be the result," the report states.
White House support for H.R. 2576 is seen by many as an acknowledgement that the healthcare law passed last year overextended eligibility for government programs.
The bill now moves to the Senate, which may be more likely to put it up for a vote given the White House's position.