Despite the expansion of health coverage under the Affordable Care Act, Community Volunteers in Medicine, which provides free care to poor, uninsured Chester County residents, has seen a steady increase in patients since 2013.

Now, given that the ACA is likely to be changed or be repealed, Community Volunteers' chief executive, Maureen Tomoschuk, fears a surge in demand.

"We're very worried," Tomoschuk said this week. Even in Chester County, Pennsylvania's wealthiest, people fall through the cracks, Tomoschuk said.

"Our concern is, with changes to the Affordable Care Act, there will be more people who need us," she said.

Republicans in Washington last week released a policy brief on their plans to replace the ACA with health savings accounts, tax credits, and Medicaid block grants to states, moves that some analysts expect to lead to fewer people with insurance.

Even with the ACA, Community Volunteers, a tax-exempt organization founded in 1998, saw its patient count climb to 3,363, between 2013 and last year, a 21 percent gain. In the current fiscal year, from July through January, the number of patients is up 16 percent, compared with the same period a year ago.

To qualify for services at the Community Volunteers clinic, which is just outside West Chester, individuals must live in Chester County, lack insurance, and have an annual income of less than 300 percent of the poverty level, or $35,640 for an individual.

Laurie Haas has been a Community Volunteers patient for almost 13 years because she has not had a job with insurance since the early 2000s. For the last decade, she has been property manager for the apartment complex where she lives, near West Chester, but does not qualify for Medicaid.

"They rescreen me every year," Haas, 54, said of the Community Volunteers' process for ensuring that patients qualify and cannot get on Medicaid.

The organization relies on volunteers, philanthropy, and donated services from health systems to care for people such as Haas. Donated services from Penn's Chester County Hospital totaled $515,956 in fiscal 2016. Main Line Health, which owns Paoli Hospital, where Haas had her gall bladder removed in 2010, donated $1.1 million in services in fiscal 2016.

Among the organization's 390 volunteers is Fred Witzeling, 78, a retired pharmaceutical executive who said he works 40 hours a month in the drug dispensary. One of Witzeling's tasks is to run a report every Monday on all the drugs that were given out so that can be reported to the companies that donated them.

A new volunteer on Monday was an adolescent psychiatrist, who will donate a half-day each month to help with Community Volunteers' expansion into behavioral health.

Community Volunteers is part of a robust health safety net in Chester County, including another free clinic in Phoenixville and two federally qualified health centers, said Jeanne Casner, director of the Chester County Health Department.

"Community Volunteers in Medicine does it in a very unique way, using a volunteer model, and are super-effective at it," Casner said.