Headquartered in Sacramento, Western Health Advantage is a non-profit HMO health plan with a community-based mission, founded in 1996 by local doctors and health care providers. WHA is consistently recognized for quality and delivering value to its members. With a focus on being a market leader in affordability since its inception, WHA serves 9 Northern California counties (Sacramento, El Dorado, Placer, Yolo, Colusa, Solano, Napa, Sonoma and Marin). The WHA provider network includes major hospitals and medical centers and thousands of local, trusted doctors and specialists from several medical groups.