WASHINGTON — Supporters of the Patient Protection and Affordable Care Act (ACA) hailed a recent Census Bureau report that the percentage of people without health insurance coverage declined by 2.9 percentage points last year, from 13.3% to 10.4%.

That’s a reduction of 8.8 million people, the biggest one-year decline ever, and part of the reason why health care employment in the United States is at a peak.

The number of uninsured declined in every state, despite the fact that there was no change in median household income or the official poverty rate, the Census Bureau said in its report, released earlier this month. Median household income in the United States was $53,660 last year, the bureau reported, and the poverty rate remained steady at 14.8%.

The Census Bureau data is based upon the bureau’s annual American Community Survey of households.

The proportion of the population with insurance was 88.5% at the end of last year, up from 85.6% a year earlier. The rate had hovered around 85% for more than a decade, though it fell as people lost jobs in the Great Recession.

The biggest gains in health insurance coverage rates last year were in private health insurance purchased directly from insurers or through the ACA exchanges, and in increases in Medicaid, which was expanded under the law. The law gave people subsidies to buy coverage and required certain employers to provide insurance.

The share of people with government plans rose to 36.5% in 2014 from 34.6% a year earlier. Medicaid coverage increased to 19.5% of the population last year from 17.5% in 2013. Medicare coverage applied to 16% of people last year.

In 2014, 66% of people had private insurance, the bureau reported. More than 55% had employment-based coverage in 2014, about the same as in 2013. At least so far, the data suggest a significant number of employers did not stop offering health insurance to their workers after government-subsidized options became available, as some analysts predicted would happen.

The biggest gains in health insurance coverage occurred last year among households with incomes less than $50,000 a year.

The ACA was intended to expand the Medicaid program to people earning less than 138% of the poverty level in every state. The Supreme Court in 2012 ruled Medicaid expansion was optional, however, and some states declined to participate in the expansion.

In June, the ACA survived its second Supreme Court challenge, with a divided court agreeing with the Obama administration that government subsidies that make health insurance affordable for millions of poor and middle-class Americans should be available ­nationwide.

In addition to increasing the number of Americans who have health insurance, the law, widely known as Obamacare, was designed to lower medical costs and put an end to insurance industry practices such as cutting off care when it gets expensive.

Despite the gains in the insured population, the Census Bureau report found that 33 million people in the United States were without insurance last year.
Obamacare’s push to get more Americans covered by health insurance was cited as a factor in the significant rise in the number of people who are employed in the U.S. health care sector.

The Labor Department reported this month that health care jobs in August hit a record as a percentage of total non-farm employment, fueled in part by an improving economy. Health care jobs made up 10.7% of all jobs in August. That’s 15.2 million people working in such places as doctors’ offices, hospitals and clinics, up from 14.7 million a year earlier, the department reported.

The ACA continues to face legal challenges. A federal judge this month ruled that the House had the right to sue the Obama administration over billions of dollars in health care spending.