While Texas continues to lead the nation in the number of uninsured residents, the percentage lacking coverage has fallen significantly since the Affordable Care Act's insurance marketplace began enrollments a year and a half ago, a study released Thursday shows.

The decline, to 16.9 percent from 24.6 percent, represents a reduction of nearly a third between September 2013 and March 2015, according to findings by the Episcopal Health Foundation and Rice University's Baker Institute for Public Policy.

"This is a dramatic drop that's unprecedented in Texas," said Elena Marks, president and CEO of the Episcopal Health Foundation and a health policy scholar at the Baker Institute. "It shouldn't surprise me because this is what was supposed to happen. But considering the weak performance of the rollout of Healthcare.gov and the persistent drumbeat against the Affordable Care Act, I am pleasantly surprised."

Marks, who co-authored the report, attributes the decrease "almost entirely" to the ability of people to buy individual insurance plans, sometimes for the first time in their lives. The drop in the uninsured rate crosses all incomes and ages, including young adults who often are seen as resistant to buying health insurance plans.

The rate of uninsured dropped by nearly a fifth for those between the ages of 18 and 44. Older Texans saw an even bigger decline as the percentage of uninsured between age 45 and 65 dropped by more than half.

Those covered under government programs, such as Medicare and Medicaid, as well as those with employer plans showed little change this year, the report found.

Economy a lift?

That is what differs so strikingly from last year. The same survey, looking at the uninsured rate between September 2013 and March 2014, found only a 1.3 percent decline, with most coming onboard through employer plans. Last year, the rate of Texans without insurance was 23.5 percent.

It is unclear exactly what has changed in the past 12 months, although there is some speculation that the state's economy was more robust last year and new hiring often came with health insurance plans. But things are shakier in the state this year, especially in the oil and gas sector. Some wonder if that may be forcing people to find their own plans.

Or it could be that people are finally getting used to the idea.

Currently, the movement is centered on the individual market. In fact, the decrease of uninsured Texans almost exactly mirrors the more than 7 percent increase in those buying individual plans.

"This is an important change," the report said.

For years, there have been plenty of insurance carriers in the state offering individual plans, but the report noted those plans were "often unaffordable or unavailable to many."

'Absolutely essential'

This is the second report released this week examining attitudes toward health insurance and its impact on Texans. On Monday, the Texas Medical Center released a Nielsen survey that found 83 percent of adults in the state think having health insurance is important, with 50 percent calling it "absolutely essential."

That same survey showed 70 percent think it's important that the nation have universal health care coverage, with 36 percent calling it "extremely important."

Some of the findings in Thursday's report remain troubling.

As of March, Texans earning the lowest incomes remain almost four times more likely to be to be uninsured than higher-income residents.

This coverage gap has grown since 2013 because, under the Affordable Care Act, households above an established threshold can buy health insurance using subsidies and those below it were supposed to be picked up by an expansion of the Medicaid program, said Vivian Ho, chair in health economics at the Baker Institute and a Rice professor of economics. She co-authored the report.

Texas is one of 21 states whose leaders chose not to expand Medicaid coverage.

"Texas' decision not to expand Medicaid leaves those at the lowest income levels with few coverage options," the report said. The study further concluded that unless the state reverses its decision or finds another way to get coverage for the poor, they "are likely to remain uninsured."

The 31 percent decrease in the rate of the uninsured in Texas is similar to drops in other states that did not expand Medicaid coverage, the report said. But it remains lower than the nation, which as a whole saw a 41 decrease, and "well below the rate of change for states that expanded Medicaid," the report said. Those states had a 53 percent average reduction in the number of uninsured.

Health economists like Ho also are keeping a close eye on the unfolding drama in Washington.

The U.S. Supreme Court is expected to rule in June on King v. Burwell, a case that challenges the financial subsidies enrollees get from the federal exchange to make insurance affordable. About 87 percent of those who enrolled through Healthcare.gov now receive a subsidy. Without them, "the entire market collapses," Ho said

'Peace of mind'

Lisa McCarter, 51, is one who would suffer. She always had health insurance through her employer. Until she didn't.

She suddenly found herself unemployed and without coverage last year when the company she was working for moved to Georgia. Starting over as an office temp, she needed to get her own coverage, but the cost was out of reach. During the 2015 open enrollment period, she signed up at Healthcare.gov and became one of the newly insured Texans.

She now pays $182 per month and even gets to see the same doctor she had before. Without her government-funded subsidy, her plan would cost $450 per month - out of reach for her tight budget.

She hates the idea of being uninsured because one big medical bill could ruin her financially.

"There's peace of mind knowing you're not going to go broke," she said.