Everything’s bigger in Texas — including the number of Texans without health insurance. But thanks to the Affordable Care Act, the percentage of uninsured Texas residents has dropped by 30 percent. That means the Texas uninsured rate has hit its lowest point in nearly two decades.

In a new issue brief from Rice University’s Baker Institute for Public Policy, researchers report that the Texas uninsured rate dropped from 26 percent in September 2013 — before the ACA’s first open enrollment period — to 18 percent as of March 2016. The decline was observed among every age, income and ethnic group throughout the Lone Star state. And researchers say it’s all likely due to the ACA.

The new numbers are based on data from the Health Reform Monitoring Survey, a quarterly survey of people ages 18 to 64 that began in 2013.

“These latest numbers confirm the continuing downward trend in the number of uninsured Texans that began as the ACA was implemented,” said Elena Marks, a co-author of the brief and president and CEO of the Episcopal Health Foundation, in a news release. “For more than a decade prior to the ACA, the uninsured rate remained above 20 percent and was rising. It’s now clear that it’s moving in the opposite direction, and the ACA deserves the credit.”

Getting into the details of the report, researchers found that between 2013 and 2016, uninsurance among Texans ages 18-64 dropped nearly one-third, with the biggest decline among those ages 50-64, who experienced a whopping 51 percent decrease in the uninsured rate. Texans with incomes between 139 percent and 399 percent of the federal poverty level experienced an uninsurance decline of 42 percent. The number of Hispanics living without insurance went down by nearly 12 percentage points.

Among the ACA mechanisms behind the dramatic declines are new premium standards and marketplace subsidies, researchers reported. For example, ACA provisions that limit premium differences based on age made health insurance much more affordable for many Texans ages 18 to 64, while marketplace subsidies enabled many low- and moderate-income households to purchase health coverage.

The ACA has also contributed to narrowing health insurance disparities in Texas. The report found significant growth in insurance rates among Hispanic residents, with the rate of uninsurance dropping by 11.9 percentage points. Still, the uninsurance rate among Texas Hispanics is about double that of black Texans and triple the rate of white Texans.

Also, because Texas legislators decided against expanding Medicaid eligibility, as is authorized via the ACA and fully financed with federal funding, many low-income Texans remain without insurance. (Quick explainer: For states that did not expand Medicaid, many of their residents now fall into a coverage gap in which they don’t qualify for marketplace subsidies nor do they qualify for Medicaid. Essentially, they’re still being priced out of the health insurance market.) According to the new issue brief, uninsurance among this population group in Texas remains “stubbornly high” at 46 percent.

“The ACA as implemented in Texas offers little hope for Texans with the lowest incomes,” Marks said in the news release. “They make too much to qualify for traditional Medicaid and not enough to get a subsidy to help pay for their premium. They’re stuck in the ‘coverage gap’ and unless Texas expands Medicaid or comes up with another system of coverage for this group, they will remained uninsured.”

Despite the good news, the latest numbers from the U.S. Census show that Texas remains No. 1 when it comes to the number of residents without health insurance.

To download a full copy of the new issue brief, visit the Baker Institute.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for nearly 15 years.