More Chronically Ill Patients Have Health Insurance After ACA, Study Finds About half of Americans have at least one chronic medical condition.

 -- About 5 percent more chronically ill people in the U.S. gained health insurance coverage after the Affordable Care Act (ACA) was implemented, increasing from approximately 80 percent to about 85 percent of chronically ill people in a new study published today in the Annals of Internal Medicine.

Chronically ill people, including people with heart disease, cancer, diabetes, asthma, kidney disease or depression, are at risk for both physical and financial consequences of not having health insurance.

With approximately half of American adults having at least one chronic illness, researchers wanted to examine if the main provisions of the ACA, including Medicaid expansion, insurance mandates and the creation of health care marketplaces, impacted this population's access to health insurance and health care.

"We wanted to focus on the chronic disease population," Dr. Elisabeth Poorman, primary care doctor at Cambridge Hospital Alliance, told ABC News today.

"By looking at this population, you can say there are millions of people who now have access for meds for diabetes, for cancer," Poorman said. "Losing coverage is not hypothetical. It means death, it means disability, it means suffering."

The researchers from the University of California San Francisco and Cambridge Health Alliance examined data compiled by the U.S. Centers for Disease Control and Prevention and state health departments to see how more than 600,000 people between the ages of 18 to 64 with at least one chronic medical condition fared in the two years before and the year after the main provisions of the ACA were implemented in 2014. Those 600,000 people were a nationally representative sample, according to researchers.

They found that insurance coverage for people with at least one chronic condition increased by approximately 5 percent in the year after the ACA was implemented, though it varied from state to state.

Almost 82 percent of the chronically ill people in the study did have insurance before the implementation of the ACA in states that expanded Medicaid, rising to 88.5 percent in the year after the ACA was implemented, according to the study findings. In states that did not expand Medicaid, that number rose from 77 percent of chronically ill people before those main provisions of the ACA were implemented to 81.2 percent after they took effect.

Under the ACA, Medicaid was expanded to include people with annual incomes below 138 percent of the federal poverty level. The law originally mandated that states had to expand Medicaid eligibility, but the U.S. Supreme Court ruled in 2012 that the federal government could not force states to expand eligibility. Almost half of the states in the U.S. are not participating in the ACA’s Medicaid expansion.

In addition, after the ACA was implemented, researchers found chronically ill patients reported slightly better access to health care, with 2.7 percent more people getting a routine checkup; and 2.4 percent more of these patients reported they did not have to forgo a doctor's visit due to cost compared to the two years before the ACA was implemented.

However, they did not find that these patients were more likely to have a personal physician after the ACA's passage. The authors acknowledged the study has limitations since the subjects self-reported via a telephone survey and they only have data from 2014 to understand the effects of the ACA's implementation.

"We wanted to evaluate the ACA and its successes and shortcomings," Poorman said. "The main question we looked to evaluate was, 'How close are we to being able to cover the sickest Americans?' And we are actually pretty far off. But there is an obvious increase in coverage in states that have initiated Medicaid expansion."

"Many people assume that a certain income level will qualify you for Medicaid and in fact this was not true prior to the ACA expansion," Poorman explained. "Medicaid eligibility was very restricted in many states, limited to those with conditions such as pregnancy, chronic disability [not chronic disease], and legally blind."

The researchers theorized that more patients did not get coverage for a variety of reasons, including patients finding it hard to afford insurance in states that did not expand Medicaid. Another factor limiting access to health insurance may be immigration status or insurance plans with high co-payments or high deductibles, the researchers said.

Christine Eibner, an economist and professor at the Pardee RAND Graduate School in Santa Monica, California, said the study is significant since it uses actual data and not just hypothetical models for its findings.

"I think one of the strong aspects to the study is that it can zero in and focus [on] patients with chronic conditions," Eibner told ABC News.

More research will be needed to understand why patients aren't getting more care and whether these numbers have continued to improve in the last two years, said Eibner, who was not involved in this study.

"What we don't know is whether how much that lack is due to access constraints," Eibner said, noting that some patients may have difficulty getting a doctor, since some physicians have not taken patients covered by newly expanded Medicaid plans due to lower reimbursements.

John Graves, an assistant professor in the Department of Health Policy at Vanderbilt University Medical Center, said new data coming out now about the ACA has given a clearer picture on health coverage after the major law's implementation, and that picture shows that people are continuing to seek out health coverage.

"This piece is in line with a general mosaic of pieces now being placed together on impacts of the ACA on patient access to care," Graves told ABC News.