Context: The Canadian Team to Improve Community-Based Cancer Care along the Continuum (CanIMPACT) is a group of researchers, primary care providers (PCPs), cancer specialists, patients and caregivers working to improve cancer care coordination between PCPs and cancer specialists. Previous research by CanIMPACT and others has identified problems related to communication, coordination, and continuity of care. Objective: Describe findings from qualitative interviews with cancer specialists on implementation of an online communication system with PCPs. Study Design: Hybrid type I effectiveness-implementation study that included a qualitative research component and a pragmatic RCT. Setting: Ottawa Hospital Cancer Program and primary care practices in the Champlain region. Population Studied: Cancer specialists (nurses, medical and radiation oncologists, program administrators). Interviews conducted with 12 cancer specialists. Intervention: Cancer-specific adaptation of Champlain BASE™ eConsult, an online communication system for PCPs and cancer specialists called “eOncoNote”. For patients receiving treatment for prostate or breast cancer, cancer specialists had an opportunity to participate in eOncoNote discussion with PCP for 4-6 months; for breast and colorectal cancer survivors, the eOncoNote discussion lasted for 1 year post discharge to the patient’s PCP. Results: Cancer specialists described limited PCP involvement in cancer care while patients received active treatment, with one-way communication and notes being “sent into a vacuum”. There was more communication with PCPs regarding patients with metastatic disease, comorbid conditions, after patients have completed treatment, or during palliative care. Patients and caregivers play a critical role in coordinating cancer care, helping to facilitate coordination. Lack of access to the same electronic medical record (EMR) among healthcare providers poses a barrier to cancer care coordination. eOncoNote had the potential to be useful tool but it was not used extensively. Conclusions: Accessing eOncoNote as a separate system was challenging to incorporate into the workflow, and cancer specialists highlighted the need for integration with their EMR. eOncoNote did not affect information sharing with PCPs, as there was limited uptake within primary care.