The Coastal Health Alliance is keeping a close watch on Washington, D.C. this week as a federal funding program that specifically supports community health centers is on track to sunset unless Congress reauthorizes the billion-dollar program by Sept. 30. Through grants doled out by the Health Resources and Services Administration, the local health group receives an annual $1.8 million, or about a quarter of its budget. The money is used to subsidize care for uninsured and low-income patients and to fund its nurses, referral coordinators and office staff. If the Community Health Center Fund were to end, community health centers around the country would stand to lose 70 percent of their federal grant funding; C.H.A. would lose about $1.2 million a year. Yet Steven Siegel, the nonprofit’s C.E.O., is confident they’ll be able to find a solution. “I don’t have any fear about this,” he said. “We have been fairly conservative and stable. We made good with what we have and haven’t gone too far out on the edge with our expense strategies. We have reserves and can weather it.” Federally qualified health centers receive federal funding through two channels: discretionary funds and funding mandated under the Affordable Care Act. The mandatory funding ended in 2015, but Congress voted to pump $5 billion into the program until the end of this month. A new bill circulating Congress, titled the Community Health Investment, Modernization and Excellence Act of 2017, would fully fund and extend the program until 2022. The Coastal Health Alliance, which serves about 5,000 patients across its three clinics, is part of a consortium of 17 community health clinics in Sonoma, Napa, Marin and Yolo Counties called the Redwood Community Health Coalition. Mr. Siegel said he and his colleagues had known all along that the program would eventually reach its fiscal cliff. But, he added, any awareness of this “seems to be lost with all the swirl of the repeal and replace efforts.”