The Congressional Budget Office (CBO) today estimated that repealing the 2010 Affordable Care Act (ACA) would increase federal budget deficits between next year and 2022 by around $109 billion, only a small change from previous estimates. The CBO suggests that this can also be considered a rough estimate for how much the ACA reduces the deficit over the same time period.

The CBO cautions, however, that its estimates are uncertain because the projected effects of the law are themselves “highly uncertain.” The law contains some provisions that are projected to cost the government money, but others that would save money or provide additional revenue.

Also updated were CBO’s estimates of the budgetary effects of just the ACA’s health insurance coverage provisions in light of last month’s Supreme Court decision, which allows states to choose whether or not to expand eligibility for coverage under their Medicaid programs.

The budget office now estimates that these coverage provisions would have a net cost of $1,168 billion from 2012 to 2022, a net reduction of about $84 billion from estimates last March. This slightly reduced spending would come about because even with some states opting out of the relatively cheap Medicaid expansion and pushing some uninsured onto the more expensive private insurance exchanges, the “lower Medicaid enrollment (is) expected to more than offset the increase in costs from greater participation in newly established exchanges.”