House Republicans poised to send a bill repealing most of the Patient Protection and Affordable Care Act to President Obama got some good news from the Congressional Budget Office, which, in contrast to a projection it released in June, now projects that undoing major parts of the landmark health law would reduce the federal deficit by more than half a trillion dollars over the next decade.

The nonpartisan agency had already projected budget savings of $474 billion last month, shortly after the Senate passed the bill, which achieves most of its budgetary effect by phasing out subsidies for the individual insurance exchanges as well as the federally-funded expansion of Medicaid.

Since that Dec. 3 estimate, the CBO has revised its estimate, projecting that the bill’s implementation would reduce the deficit by an additional $42 billion over the next decade, for a total of $516 billion.