Introduction:Evidence-based practice is necessary for improving chronic disease prevention, reduction, and management while simultaneously lowering care costs.Patient-centeredness encompasses one of three essential and overlapping components of evidence-based practice, the others being clinical expertise and scientific/ research evidence. While patient-centered care was placed at the center of the Joint Commission of Pharmacy Practitioners Pharmacists' Patient Care Process (PPCP), few studies investigate the concept's meaning in outpatient pharmacist care.Objectives: This study explores the meaning of patient-centeredness from the perspectives of patients and their pharmacists participating in outpatient care consistent with the PPCP, and compares the elements that matter most between these two groups.Methods: Data for this exploratory QUALquan mixed methods study were collected via in-depth interviews designed to elicit perceptions of what matters to patients in pharmacist care from a purposive sample of adult patients with multiple chronic conditions and their outpatient pharmacists in the United States. Data were assessed using directed content analysis informed by 40 seminal patient-centeredness concepts from the health professional literatures of medicine, nursing, and health policy.Results: Data analysis produced 13 distinct superordinate concepts representing the meaning of patient-centeredness in the context of the PPCP. The perceived importance of the patient-centeredness superordinate concepts was generally consistent between patients and pharmacist groups except for "Therapeutic Alliance," "Care Coordination and Integration," and "Care Experience." Conclusion: This study's superordinate concepts of patient-centeredness adds clarity for what matters to patients in pharmacist care encounters, key elements for organizing team-based systems to meet the unique needs of each patient, and upstream factors that can facilitate or prevent patient-centered care. Future research should assess the reproducibility of the findings, explore reasons behind patient-pharmacist priority differences, and evaluate the resulting impact.