The non-partisan Concord Coalition on Monday urged lawmakers against tinkering with the tax on high-end health plans contained in reform legislation that passed the House on Sunday.
The group contends the tax is the "single most important cost control measure in the legislation" but feared political pressure would force lawmakers to weaken the levy before its 2018 effective date.
"Opponents are already pointing out that they will have plenty of opportunities to kill, or further dilute, the tax," the group said in prepared remarks.
Ways and Means Chairman Sandy Levin (D-Mich.) is one such lawmaker looking to tweak the tax.
"The advantage of 2018 is we'll be able to look at it -- and we will," he recently told reporters.
Levin contends that roughly 40 percent of all health plans will be subjected to the tax over time because of the way it is indexed for inflation.
The head tax writer hails from a union-heavy state and union leaders had to be coerced into backing the tax.
In a recent meeting with reporters, Levin had little good to say about the tax.