Background: Despite recommendations to discuss the cost of care (CoC) with patients with cancer, little formal guidance is available on how to conduct these sensitive conversations in ways that are acceptable to both patients and providers. Objective: To explore the perspectives of patients and medical and nonmedical cancer center staff on CoC conversations. Design: In individual interviews, participants were asked to discuss the content of, timing of, and ideal person to hold CoC conversations. Interviews were transcribed verbatim. Content was analyzed to identify emerging essential elements. Setting: Division of Preventive Medicine, University of Alabama at Birmingham. Participants: 42 women aged 60 to 79 years with a history of breast cancer and 20 cancer center staff (6 physicians, 4 nurses, 5 patient navigators, 3 social workers, and 2 billing specialists). Results: Both patients and providers identified reassurance and action as essential elements of CoC conversations. Participants expressed the importance of reassurance that recommended medical care would not be affected by affordability challenges. Action was intended as discussions on ways to help patients cover treatment-related costs, such as discussion of payment plans or linkage to financial resources. Optimal timing for CoC conversations was felt to be after an initial consult visit but before treatment started. The person to hold these conversations should be compassionate, helpful, and knowledgeable of the patient's specific situation (for example, treatment plan, insurance coverage) and of the resources available to attain the patient's goals of care. Limitation: Interviews were limited to older breast cancer survivors and staff at 1 institution. Conclusion: Conversations about CoC extend beyond discussing costs and must be sensitive to the vulnerability experienced by patients. These findings can guide training of personnel involved in CoC conversations.