The only hospital in Martin County, N.C., closed in 2023, but the electricity is still on inside. Air conditioning continues to keep its empty patient rooms cool. And the county still pays the bills for the building’s medical gas system.

That is because the people of Martin County, in rural eastern North Carolina, have been determined to keep the beige brick building from deteriorating — and to somehow reopen their hospital, which had been struggling financially for years.

When North Carolina expanded Medicaid later in 2023, after the hospital shuttered, offering government health insurance to the state’s low-income adults, Martin County saw an opportunity. Plans materialized to partly reopen the hospital, largely because federal dollars were pouring into the state to cover patients’ care under Medicaid.

But those plans are now in jeopardy, as is Medicaid coverage for hundreds of thousands of North Carolina residents, after Congress passed President Trump’s sweeping domestic policy bill. To help pay for tax cuts, the bill slashes federal spending on Medicaid, leaving states that expanded the program under Obamacare in a particularly difficult spot.

If Medicaid expansion is eliminated in North Carolina, Martin General Hospital almost surely will not reopen — “a catastrophic and deadly consequence,” said Paul Roberson, a real estate agent and community leader in Williamston, where a sign in front of the hospital reads, “CLOSED. If you need immediate assistance, dial 911.”

“Not having the hospital here is costing lives,” Mr. Roberson said, noting that the nearest hospital was about a 30-minute drive away. “This is the most important thing for us.”