I doubt many realize it, but some of the biggest beneficiaries of the Affordable Care Act, better known as Obamacare, are local taxpayers in Cook County.

In 2009 before implementation of Obamacare, county taxpayers subsidized Stroger and Provident Hospitals and their allied clinic system to the tune of $481 million a year.

This year that subsidy is down to $111.5 million, a reduction of more than 75 percent.

Most of that difference is directly attributable to the Affordable Care Act, which provided medical coverage to previously uninsured poor people through Medicaid, in the process shifting the cost of their care to the federal government.

OPINION

Now that Republicans in the U.S. House of Representatives have cleared the first hurdle in repealing and replacing Obamacare, it’s those same Cook County taxpayers who will be at risk of having to make up the difference if the federal coverage goes away.

On Monday, Cook County Board President Toni Preckwinkle stood with Democratic members of the Illinois Congressional delegation to slam the House vote as a “shameless act of political cowardice” for endangering health care for millions of Americans.

Indeed, the most important reasons for preserving the Affordable Care Act, or at least fixing it sensibly, relate to the harm to individuals that will come from removing health care coverage for those who otherwise would have none.

But the dollar impact on local taxpayers here shouldn’t be overlooked.

Some of you surely remember the time not that long ago when the county hospitals were a constant source of handwringing as elected officials wrestled with huge deficits and how to close them.

There have been other improvements to the county health system in the intervening years — a move to managed care, improved billing and other operational efficiencies — but the big financial difference is the decrease in the number of uninsured.

Before the Affordable Care Act, fewer than half the people served by county hospitals were insured, said Dr. John Jay Shannon, chief executive officer of Cook County Health and Hospitals System.

Today nearly 70 percent of the county’s patients have insurance, he said. Most of them get their coverage through Medicaid.

“Make no mistake, the Affordable Care Act has been a godsend both to the patients we serve and to our health care system,” Shannon told a luncheon audience at the City Club of Chicago.

Shannon estimates the Republican plan would cost Cook County at least $300 million in annual revenue and additional costs.

That could grow as high as $800 million depending on how many more patients seek charity care from the county if other local hospitals fail to fill the void, he said.

Shannon is projecting that 54,000 adults would be at risk of losing the coverage they now have through the county’s managed care health plan, known as CountyCare, under the GOP bill. That’s out of a total of 140,000 enrollees.

The county’s cost estimates must be taken with a grain of salt at this point because local officials admit they don’t have a strong understanding yet of how the House plan would work, and more important, the Senate is probably going to greatly revise the legislation.

But it’s obvious that any plan that drastically reduces the number of uninsured is going to have its greatest impact in urban areas where there is a larger concentration of poor people, such as Chicago.

Asked how she would plug the $300 million hole if it came to pass, Preckwinkle answered plainly: “I don’t know.”

But she seemed to rule out a property tax increase.

“There are no votes on the Cook County Board of Commissioners to raise property taxes,” she said.

Maybe not, but if the federal government pulls its support for health care coverage, something will have to give.