This story was corrected on July 16, 2009. An explanation of the correction is at the end of the story.

Since opening last June, the Mary's Center Primary Care Clinic in Silver Spring has provided free or reduced-cost health care to 2,500 uninsured or underserved residents, relieving the growing burden on area hospital emergency rooms, center officials say.

More than 80,000 Montgomery County residents lack health insurance, said Uma Ahluwalia, the director of the county Department of Health and Human Services, who praised the nonprofit's efforts during the center's one-year anniversary celebration Thursday.

Maria Gomez, who founded the first center in D.C. in 1988, thanked private and public supporters for their role in keeping the initiative alive.

Relying on the donations, the center has grown from a nursing staff of one when the center opened into a larger operation with two doctors, a pair of nurses and a variety of social services support staff that help patients with everything from recuperating from injuries to getting help in abusive relationships or homelessness, said the facility's co-founder, Maria Lewis.

"The [original] clinic in D.C. was seeing a lot of Maryland patients," she said of the decision to fund the Flower Avenue facility. "[Of those patients] we see a majority of uninsured and underserved patients."

By providing care to lower-income residents and the uninsured, the center is also able to reduce congestion in local hospital emergency rooms, she said. Many residents without insurance go to the ER for regular health care, which costs hospitals money and takes time and resources away from legitimate medical emergencies, she added.

"The hospitals were seeing a lot of patients who shouldn't be in the emergency room; people with sore throats, diabetic patients … people who need a primary care physician but couldn't afford it," Lewis said.

College Park resident Elizabeth Odeigah, a nurse who has been out of work, checked into the emergency room at Washington Adventist Hospital last March for arthritis that had affected her knees.

"When I was discharged after five days they asked me to come here [in the future]," she said. "It's been great. The doctor, she put me on some pills for my pain and she referred me to an orthopedic surgeon."

Thawan Phongsuwan and his wife, Zenir, were referred to Mary's Center by a friend. Thawan suffered two heart attacks and underwent open heart surgery at Washington Adventist before he lost his job and health insurance about a year ago.

"He needed prescriptions, so we took him here because I couldn't afford to take him to a cardiologist," Zenir Phongsuwan said of her husband. "I hesitated at first, but now we love to come here; this place is like a family."

Recognizing the symbiotic relationship that exists between Washington Adventist Hospital's emergency care capacity and Mary's Center's efforts, the hospital has given the center $500,000 in grants, half when it opened and half in February. The hospital spends $25 million annually providing emergency and non-emergency care to uninsured patients, according to hospital accounts.

With these and other funds, Gomez and the Mary's Center staff hope to welcome additional nurses and a full-time pediatrician to the facility soon. Such a move would allow it to take in more patients and capitalize on the center's growing popularity in the predominantly lower-income area.

Del. Heather R. Mizeur (D-Dist. 20) of Takoma Park, who attended at the celebration, called the center a "crown jewel" for providing quality, affordable care to the county's sizeable lower-income population.

"It's not just that the doors are open and this is their provider of last resort," Mizeur said. "This is their provider of first choice."

Correction: A previous version of this story included an incorrect sum for the amount of money donated by the hospital to Mary's Center. The center has received $500,000 in grants from the hospital. The story also incorrectly stated the use of money the hospital spends to serve the underinsured. The $25 million the hospital spends annually to serve people who are uninsured includes emergency and non-emergency care.