We describe a health plan-based herbal resource program designed within the framework of a systems approach to population health improvement. The setting is a not-for-profit, consumer-governed health plan in the Midwestern US. Telephone-based, centralized services facilitate a process of access, communication, documentation and intervention in the area of complementary and alternative medicine (CAM) use. A herbal-trained resource pharmacist is employed to provide evidence-based information on CAM products, when available, to patients and healthcare providers, educate patients who have chosen to self-medicate with CAM products for chronic conditions, and assist patients in the selection of quality CAM products prescribed by a physician. Three case studies are presented as examples of how the program is accessed, the intervention is tailored to individual needs, communication is established, documentation is organized and support is facilitated.In the year 2002, of the 61 860 contacts/encounters to the phone line, 1190 were with the herbal resource pharmacist. Of these, 68% were with patients and 31% with healthcare providers. Satisfaction of patients utilizing this resource appears to be high, with 60% rating the service as exceeding their expectations, 96% indicating they would refer the service to an acquaintance, and 100% of those surveyed indicating they improved their understanding of use and safety of herbal medicine and other natural products.An herbal resource support program appears to effectively provide access to timely information for both patients and providers. This approach, designed to meet the CAM information needs of both patients and providers, appears well positioned within the context of a health plan as the service is supportive to all users.