Here is the CBO report (pdf warning)
I clip and past a dramatic graph
They also estimate that it has caused 12 million more people to have insurance. This is the net increase subtracting cancelled non ACA compliant pseudo insurance. I wonder if the official 12 million estimate will convince people to stop saying that the increase is around 10 million (I doubt it). My back of the envelope calculation was 13-14 million.
Notably ACA critics claimed that the old CBO estimate, which implied that Obamacare would reduce the deficit, was bogus. Well it was incorrect (making predictions is difficult especially about the future) but because it underestimated the reduction of the deficit due to Obamacare.
The CBO cost estimate of costs through is also 7% lower than their estimate made April 2014. That is, the latest estimate of the costs 2015-2024 is reduced by $101 billion (which isn’t pocket change even for the US Federal Government). Also and in addition, the new CBO estimate of the number of people who will gain insurance in 2024 due to the ACA is one million higher than the estimate made long ago in April 2014, so one million more people insured for 101 billion fewer dollars. Not bad at all.