The House Armed Services Strategic Forces subcommittee capped all spending on all "missile defense equipment" required to support the missile shield, dubbed by the White House as the European Phased Adaptive Approach (EPAA).
The NATO requirement was part of the subcommittee's version of the fiscal 2013 defense spending bill released Wednesday.
President Obama wants to begin deploying Navy destroyers armed with AEGIS anti-missile systems to Europe this year as part of the plan.
The White House wants all land and sea elements of the missile shield in place by 2020.
That network of sea and land-based missile launchers stationed in Europe will be geared primarily to counter long-range missile threats from Iran.
However, doubts on Capitol Hill are already beginning to surface on whether the administration can adhere to the aggressive timelines it has set.
Deep cuts to defense spending proposed by the White House have also added to that uncertainty. The Department of Defense has included roughly $250 billion cuts as part of its fiscal 2013 budget plan sent to Congress in February.
That is half of the $500 billion the White House wants DOD to trim from its coffers over the next decade.
Those cuts, introduced as part of the administration's debt ceiling deal last year, hit missile defense accounts particularly hard, according to House lawmakers.
Financing for missile defense dropped $400 million in fiscal '13 compared to funding levels set last fiscal year, according to the subcommittee.
Those accounts are expected to drop by a total of $3.6 billion over the next five years, as a result of the defense cuts introduced under the Budget Control Act.
Paying for a large-scale missile shield in Europe under those fiscal conditions will be next to impossible without buy in from NATO.
To that end, DOD has yet to provide Congress or the White House a firm cost estimate for how much the missile shield will cost.
"The committee is concerned that when this [EPAA] commitment was made, there was no clear understanding of the cost [involved]," lawmakers wrote.
The Office of Management and Budget first asked the Pentagon to wrap up a comprehensive cost estimate for the missile shield program back in December 2009.
OMB requested an EPAA cost estimate again last December.That assessment was due in March, according to House lawmakers.
"That briefing has not been provided," according to the draft legislation. Congress nor the White House has received "a complete explanation from the Department of all of the U.S. capabilities that will be available to support the EPAA," it adds.
That information will be critical to providing NATO the pre-financing request called for in the subcommittee's defense bill.