BOISE, Idaho — The estimated number of Idahoans who earn too much to qualify for Medicaid has dropped at least 20 percent over the past four years and possibly as much as 35 percent, the Idaho Department of Health and Welfare said Monday.

There are currently between 51,000 and 62,000 low-income individuals who receive no health care benefits or assistance. A 2014 study by actuarial firm Milliman showed 78,000 Idahoans were in the so-called Medicaid gap based on the state’s census and demographic data.

“Ultimately, it’s always going to be an estimate based on the data that we have,” said Niki Forbing-Orr, the department’s spokeswoman. “That 78,000 was a fairly good estimate …but we’ve been working with this new number informally for a few months now.”

The updated Medicaid gap population estimate is based on recent data from people enrolled in the Supplemental Nutrition Assistance Program, otherwise known as food stamps. Forbing-Orr says SNAP has seen a drop in participants since 2014.

Food stamp recipients “have to go through all the eligibility and they have to get certified regularly,” Forbing-Orr said. “So that’s the best information that we have about households in Idaho, and estimating if they would be in the gap.”

Health care advocates have long pleaded with the state’s GOP-controlled Legislature to find a way to provide medical care to those adults because their medical bills are paid for by the state’s counties and people who have private insurance.

However, Idaho’s Republican-dominated Legislature has remained resistant to the most popular option — expanding Medicaid eligibility requirements as allowed under the Affordable Care Act — due to their hesitancy to using the federal government and relying on former President Barack Obama’s health care law.

While this year’s legislative session saw multiple lengthy debates about addressing the Medicaid gap population, lawmakers ended their legislative session without passing a policy proposal to deal with the problem.