Maryland has saved nearly half a billion dollars in hospital costs over the last 15 years thanks to expanded insurance coverage.

The estimate comes from medical advocacy group Maryland Healthcare for All!, which will present its findings to the Maryland General Assembly later this week.

Over the 15 years, the state reduced the number of uninsured from 13% to 6%.

“When people go to the hospital without health care coverage under uncompensated hospital care, that's a hidden health care tax, because it goes right into all of our health insurance premiums,” Vincent DeMarco, president of Maryland Healthcare for All! said. “Because of these health care expansions we have decreased uncompensated hospital care.”

Maryland, along with the federal government, has implemented several programs to insure people who previously did not have coverage.

The state expanded Medicaid in 2009 and established a small business insurance premium subsidy program as well. Those initiatives paired with the federal Affordable Care Act significantly decreased the number of uninsured people living in Maryland.

“While we cannot assume that the major health care reforms outlined in the study are the only factors impacting hospital uncompensated care, the trends above show that they certainly represent an impact,” the study states. “The estimated savings from this report is a conservative estimate.”

DeMarco said Maryland could see even more savings, which in turn could be passed on to consumers, if the state can bring its uninsured percentage to zero.