Nearly 17 million Americans got health insurance under the Affordable Care Act after the new insurance exchanges opened up, according to an independent analysis published Wednesday.
The goal of the law, known widely as Obamacare, was to increase the number of Americans who have health insurance, put an end to industry practices such as cutting off care when it gets expensive, and to lower medical costs.
It's worked to get more people covered, the Rand Corporation found in its study.
Between September 2013, right before the exchanges first opened, and February of this year, 22.8 million people who did not have health insurance before got coverage, the Rand team reports in the journal Health Affairs. And 5.9 million lost coverage. That makes for a net gain of 16.9 million people.
But most didn't buy their insurance on the exchanges. Instead, they got insurance from their employers, just like the majority of Americans.
The study is the first to look at "insurance transitions" -- when people drop one form of coverage for another.
"While the vast majority of those previously insured experienced no change in their source of coverage, 5.9 million people lost coverage over the period studied, and 24.6 million moved from one source of coverage to another," the researchers wrote in the journal Health Affairs.
"The Affordable Care Act has greatly expanded health insurance coverage, but it has caused little change in the way most previously covered Americans are getting health insurance coverage," said Katherine Carman, an economist at RAND who led the study team, said in a statement.
"The law has expanded coverage to more Americans using all parts of the health insurance system."
Carman's team found that 11.2 million people bought health insurance on the exchanges -- the online marketplaces where people can buy private insurance coverage and apply for an often hefty federal subsidy. This backs up the federal government's estimate of 11.7 million.
Another 12.6 million got Medicaid in the states that have opted to make the state-federal health insurance plan more widely available. About half of them had been covered before by some other insurance, while half were uninsured.
In 2013, the Census Bureau estimated that more than 47 million Americans lacked health insurance coverage, or about 15 percent of the population. The Gallup Corporation and HHS both estimate that about 13 percent of American adults still lack health insurance coverage.
The Obama administration released another piece of good news for its health care policies this week.
Health and Human Services Secretary Sylvia Burwell said a program meant to save money by coordinating patient care better generated more than $384 million in savings in its first two years of operation.
The report from L&M Policy Research, LLC, found that Pioneer Accountable Care Organizations -- groups of providers who agree to be paid a lump sum to take care of a patient as opposed to charging for individual treatments and services -- saved Medicare about $300 per beneficiary per year during 2012 and 2013.