“The recent decision of a three-judge panel in the Halbig case, if it prevails, would have a direct effect on the availability of subsidies under the Affordable Care Act (ACA). People buying coverage on their own in insurance exchanges run by the federal government would be ineligible for income-based subsidies. Depending on how you count, that would take premium subsidies away from 4.6 million people in 34 states, or 4.7 million people in 36 states if you count New Mexico and Idaho (which have signaled their intention to operate their own exchanges but are still using the federal marketplace).
Many more people are eligible for subsidies but haven’t yet signed up. We estimate (using the approach described here that a total of 9.5 million uninsured people are eligible for subsidies in federal marketplace states (or, 9.7 million people if you include New Mexico and Idaho).
Since many low and moderate income people would have difficulty affording insurance without the subsidies, this would no doubt alter the extent to which the ACA is reducing the number of Americans who are uninsured, which recent surveys peg at about 8 to 10 million.
But, there would also be two important side effects of the Halbig case.”