An updated analysis from the Congressional Budget Office (CBO) on the effects of repealing the Affordable Care Act (ACA)’s individual mandate found such a move would reduce federal budget deficits by $338 billion between 2018 and 2027, while also increasing the number of uninsured Americans by 13 million.

The new analysis differs from the CBO’s Dec. 2016 report, which projected greater savings ($416 billion) and a larger drop in coverage (16 million). The new projections, CBO said, were based on updates on the federal costs of the ACA’s premium support subsidies as well as the expectation the reaction to eliminating the mandate would “phase in more slowly” than previously believed.

The loss in coverage would be less than other versions of ACA repeal-and-replace legislation introduced by Republicans earlier in 2017, such as the “skinny repeal” plan that eliminated the individual and employer mandates and the ACA’s medical device tax. Some of those plans were projected to destabilize the individual market in some parts of the U.S., which the CBO said wouldn’t happen if the mandate is eliminated.

“Nongroup insurance markets would continue to be stable in almost all areas of the country throughout the coming decade,” the report said.

This is in contrast to similar approaches in individual states. Both New York and Washington tried requiring insurers to accept all customers, regardless of pre-existing conditions, without a mandate. The result in both was a “death spiral,” with Washington’s individual market losing all its insurers within four years.

Coverage losses would begin in 2019, with three million fewer people having nongroup coverage (including through the ACA exchanges) and one million fewer people being covered by Medicaid. By 2027, 5 million fewer people would be covered by Medicaid, five million fewer people would have nongroup coverage and two million will have been dropped from employer-based insurance plans.

For those remaining in the markets, monthly premiums would continue to increase The CBO estimated rates would rise by “about 10 percent in most years of the decade.”

The savings for the federal budget would be driven by fewer people buying ACA exchange insurance with the help of a federal subsidy, which would reduce deficits by $185 billion over the 2018-2027 time frame. Reduced Medicaid spending would save another $179 billion. These would be partially offset by $43 billion less being collected in individual mandate penalties.

More uninsured means more uncompensated care costs for hospitals. The CBO reflects this, saying Medicare would have to spend $44 billion more between 2018 and 2027 as Disproportionate Share Hospital (DSH) payments increase.

The $338 billion in deficit reductions could spur Republicans to include a repeal of the mandate in their tax cut legislation as a way to offset the budgetary impact of eliminating other deductions—including one which may adversely affect medical school students. House Speaker Paul Ryan has said mandate repeal is being discussed in the House’s version of a tax bill.

“We're making people buy something they can't afford and don't want,” Ryan told reporters on Nov. 9.

In the Senate, however, it doesn’t appear to be gaining as much traction. Soon after Ryan’s comments, Sen. Bill Cassidy, MD, R-Louisiana, told reporters eliminating the individual mandate wasn’t part of the Senate’s tax plan.