From Day One, Sen. Marco Rubio, R-Fla., has repeatedly promised that no illegal immigrants would receive any federal benefits if his Schumer-Rubio immigration bill became law. “Temporary-status immigrants will be barred from receiving federal benefits, and this legislation extends that prohibition to include ObamaCare,” a FAQ on Rubio’s website reads.

But the Congressional Budget Office begs to differ. It notes that the actual legislative language in Schumer-Rubio is far less clear than Rubio lets on. And the Senate Judiciary Committee rejected an amendment sponsored by Sen. Ted Cruz, R-Texas, that would have made it crystal clear that currently illegal immigrants were ineligible for all federal means-tested welfare programs. The CBO concludes:

If S. 744 was enacted, executive branch agencies would probably face pressure from states and other stakeholders to provide people who are lawfully present in the United States with the federal benefits that are available to qualified aliens, including assistance provided through Medicaid, CHIP, SNAP, student loans, and Pell grants. For this estimate, CBO assumed that such agencies would settle on an interpretation of the law that permitted some individuals with RPI, blue card, or V-visa status to receive benefits from those programs—as well as from other programs from which those people would not be explicitly excluded by S. 744 or existing law.

As a result of this reading, the CBO found that over the next ten years, Schumer-Rubio would result in $82.3 billion more in Obamacare subsidies, $29.3 billion more in Medicaid spending, $6 billion more in food stamp spending, $5.1 billion more in unemployment insurance spending and $3.5 billion more in child nutrition spending. Newly legalized immigrants would also be eligible for the Earned Income Tax Credit, which would cost the federal government $126.8 billion.

All told, the CBO estimates that Schumer-Rubio would grow government spending by $258.9 billion. And none of that total includes the cost of the additional border-security items in the bill.