Under the Democratic Party’s sweeping overhaul of U.S. health care, West Virginia is to provide Medicaid health benefits to an estimated 130,000 more low-income residents.

In the early years of the expansion, the federal government — well, federal taxpayers — would cover the additional cost.

But in later years, the state — well, state taxpayers — would shoulder a share of those costs.

How much would this cost? Nobody knows.

The optimistically named Affordable Care Act expanded Medicaid because uninsured people go to emergency rooms when they need care. Caring for the uninsured costs money.

As the Daily Mail reported, it was once estimated that expanding Medicaid could save $288 million on charity care in 2014 — and still more later.

Estimated, estimated, estimated.

But existing Medicaid programs have been the fastest-growing cost in state budgets, surpassing even public education. West Virginia has not been able to accurately foresee the costs of the program it has.

Gov. Earl Ray Tomblin wants to know what the state will be getting into if it expands Medicaid. Taxpayers should want to know, too.

Accordingly, the state will pay experts more than $800,000 to get a better fix on the situation.

That’s a good idea. After all, there are at least two factors that could cause costs to zoom.

First, West Virginia has long paid health care providers far less than it costs them to treat Medicaid patients. Some doctors refuse Medicaid patients for that reason.

The cost of the current program is understated.

Second, the designers of the Affordable Care Act simply assume that if uninsured people get Medicaid coverage, they will go to the doctor, follow medical

advice and improve their health, and thereby cut health care costs in the long term.

Big assumption.

It could carry big costs.

— Distributed by The Associated Press