California’s embrace of the Affordable Care Act has allowed millions of residents to enroll in health coverage, with low-income residents and people of color seeing the largest drops in the uninsured rate, a new report says.

Statewide, the number of uninsured Californians dropped to 9.5 percent in 2015, the lowest percentage since data has been collected, according to the research from the UCLA Center for Health Policy.

Those with incomes below 138 percent of the federal poverty level ($21,984 annually for a family of two) and under age 65 were the most likely to gain insurance between 2013 and 2015, researchers found. The uninsured rate for these residents fell from 22.6 percent to 12.8 percent during those two years.

The uninsured rate also dropped significantly for most racial and ethnic groups, falling nearly 7 percentage points among Asian-Americans and African-Americans, and 6.5 percentage points among Latinos.

“The evidence shows that the Affordable Care Act has opened the doors to groups who have been historically shut out from health insurance coverage,” said Ninez Ponce, associate director of the UCLA Center for Health Policy Research.

The insurance gains can largely be attributed to the state’s expansion of Medi-Cal, a low-income health program, and income subsidies for Covered California insurance. California implemented these two initiatives as part of the federal Affordable Care Act.

The researchers used data from the 2015 California Health Interview Survey, which surveyed 21,444 households in the state.