Politico:

According to the new White House budget, from the time the exchanges open in 2014 to 2021, the administration expects to spend about $606 billion on subsidies, a massive commitment of federal resources.

That's about 27 percent more than the $478 billion projected in the president's budget last year, and 65 percent more than the $367 billion for the same period in the 2012 budget.

But experts -- and government actuaries -- attribute much of the jump to the Supreme Court's changing the rules of the game when it made the Medicaid expansion under the health law optional for states.

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The Congressional Budget Office estimates that it will cost about $9,000 in subsidies for a person who would have qualified for Medicaid under the expansion -- compared to $6,000 for Medicaid coverage.

On the other hand, CBO projects that 3 million fewer people will be covered in 2022 because of state decisions not to expand Medicaid. On balance, CBO projects the ruling will save the government about $80 billion through 2022.

The Supreme Court ruling might be "a blessing in disguise," said Len Nichols, director of the Center for Health Policy Research and Ethics at George Mason University and a supporter of the health law. "It provides some savings upfront, which is welcome and will give states some time to buy in."

But the budget makes the numbers difficult to compare. It projects the expected premium subsidies specifically but does not break out the expected spending on the Medicaid expansion in a similar way. This year, the budget did revise down its total expected Medicaid spending in 2020 by about $135 billion, although the reduction is only partly due to consequences from the court.

The truth is that the cost is still a guessing game. States are still trying to make up their minds on what to do. And it's not known how many people will enroll in the state-based exchanges, with or without Medicaid expansion.