NASHVILLE, Tenn. — Although the number of uninsured and the cost of coverage have ballooned under his watch, President George W. Bush leaves office with a health-care legacy in bricks and mortar: He has doubled federal financing for community health centers, enabling the creation or expansion of 1,297 clinics in medically underserved areas.

For those in poor urban neighborhoods and isolated rural areas, including Indian reservations, the clinics are often the only dependable providers of basic services like prenatal care, childhood immunizations, asthma treatments, cancer screenings and tests for sexually transmitted diseases. As a crucial component of the health safety net, they are lauded as a cost-effective alternative to hospital emergency rooms, where the uninsured and underinsured often seek care.

Democrats on Capitol Hill are proposing even more significant increases, making the centers a likely feature of any health care deal struck by Congress and the Obama administration.

In Nashville, United Neighborhood Health Services, a 32-year-old community health center, has seen its federal financing rise to $4.2 million, from $1.8 million in 2001. That has allowed the organization to add eight clinics to its base of six, and to increase its pool of patients to nearly 25,000 from 10,000. Still, says Mary Bufwack, the center's chief executive, the clinics satisfy only a third of the demand in Nashville's pockets of urban poverty and immigrant need.

As governor of Texas, Bush came to admire the missionary zeal and cost-efficiency of the not-for-profit community health centers, which qualify for federal operating grants by being located in designated underserved areas and treating patients regardless of their ability to pay. He pledged support for the program while campaigning for president in 2000 on a platform of "compassionate conservatism."

The centers now serve one of every three people who live in poverty and one of every eight without insurance. But a study released in August by the Government Accountability Office found that 43 percent of the country's medically underserved areas lack a health center site.

Recent job losses, meanwhile, are stoking demand for the clinics' services. The United Neighborhood Health Services clinics in Nashville have seen a 35 percent increase in patients this year, with much of the growth from the newly jobless.

"I'm seeing a lot of professionals that no longer have their insurance or they're laid off from their jobs," said Dr. Marshelya D. Wilson, a physician at the center's Cayce clinic. "So they come here and get their health care."