Obamacare will incur higher costs and insure fewer people than projected last year, Congress' official budget agency projected Thursday.

However, insurance costs under the Affordable Care Act are still expected to be lower than projected when the law was enacted in 2010.

The Congressional Budget Office, Congress' nonpartisan budget agency, released estimates Thursday afternoon showing that the net cost of insuring people through Obamacare will be $136 billion higher than previously expected, totaling $1.34 trillion from 2016 to 2025.

The law is now expected to reduce the number of uninsured people by 24 million in 2025, down from the 25 million projected last year. That change reflects the expectation that fewer people will have coverage through their employers and through the health insurance exchanges created by Obamacare, while 4 million more will get coverage through Medicaid.

This year, 12 million people will get health insurance through the exchanges set up by Obamacare, the CBO projected. That is down from the 13 million enrollees the office projected in January and a huge cut from the 21 million it estimated last year.

The exchanges signed up 12.7 million people through open enrollment that ended on Jan. 31. However, it is not clear how many of those will pay their premiums.

The administration set a goal of having 10 million people pay for their insurance by the end of this year. The administration already announced that 8.8 million people have paid for their premiums at the end of 2015, missing a goal of 9.1 million people.

"CBO's new projections show that the law is working to cover the uninsured, while costing less than expected," said spokesman Aaron Albright. "These new estimates find that the law's coverage provisions will cost 28 percent less in 2019 than in CBO's original projections."

More people will get insured through the Medicaid expansion in Obamacare, the budget office determined, partly because they now see slower wage and salary growth in the future, meaning that more people will be eligible for the low-income health program.

While more will get insured through Medicaid, fewer are expected to get coverage through the exchanges. Last year, the agency projected that an average of 15 million people would get subsidies for insurance purchased through the exchanges in 2016. Now, it sees just 10 million people getting subsidized coverage.

That drop-off is not all bad news, however. One of the reasons that fewer will be going online to get insurance through the exchanges, according to the CBO, is that not as many people are expected to lose coverage through their employers. In turn, fewer people will take up employment-based coverage in the first place because they will be eligible for Medicaid.

The news comes a day after the sixth anniversary of the healthcare law, which the public is still bitterly divided over. The law has extended coverage to about 20 million people, with more than half of that coming from the Medicaid expansion.

So far about 30 states and the District of Columbia have expanded Medicaid.

The Department of Health and Human Services said the projections show the law is working.

? Robert King contributed to this report.