More than 12 million people will gain health insurance under the Affordable Care Act this year, according to new projections released by the Congressional Budget Office Monday. And millions more stand to benefit from the law over the next decade.

At the same time, the law's costs to the federal government are shrinking. According to the new projections, the federal government will spend more than $100 billion less on Obamacare's coverage provisions through 2024 than previously projected. That includes a downward estimate of about $5 billion this year. Overall, spending on the federal and state insurance exchanges are projected to cost 14% less than originally forecast.

The CBO said plans offered through the exchanges are narrower, allowing companies to keep premiums low and the federal government to pay less in subsidies. The lower spending projections on the Affordable Care Act will help shrink deficits overall. The CBO said the federal government will now run a deficit of $492 billion in fiscal year 2014, which is almost a 33% decrease from 2013.



Through both the federal and state insurance exchanges and the expansion of the federal Medicaid program under the law, the CBO projects more than 12 million people now have insurance who wouldn't have normally been covered in the absence of the law. The CBO also projects 19 million people will gain coverage by 2015, 25 million more by 2016, and 26 million more by 2026.

In 2014, according to the CBO, about 6 million people gained insurance from the exchanges and close to 7 million people benefitted from the Medicaid expansion. Those gains reduced the number of uninsured in the U.S. to 42 million —16% of the population. By 2024, the CBO projects, about 89% of U.S. residents will have health insurance.

Here's a chart from the CBO showing the parallel universe between a U.S. with the Affordable Care Act in 2024 and one without it:

There's one key difference between the CBO's projections and a study released last week by RAND Corp., which said a net 9.3 million people had gained insurance coverage from September through March: The RAND study said most of those who gained coverage did so through employer-sponsored coverage, something the CBO said did not contribute to any relative gains in coverage.

The Obama administration has spent much of the past two weeks trumpeting the law in spite of a disastrous rollout. Former Secretary of Health and Human Services Kathleen Sebelius, who resigned last week, said 7.5 million people had enrolled in plans through the exchanges by the end of the law's first open enrollment period on March 31.