Background: Interdisciplinary rounds (IDR) are increasingly employed by hospitals; however, there is no formal definition, structure, or framework. Objective: The purpose of this observational study was to document the heterogeneity of IDRs and assess the different characteristics associated with IDR functions. Designs, Settings, and Participants: Observation of IDR occurred at 27 hospitals that were purposively selected to ensure a mix of the following criteria: geographic region, provider type, for-profit status, population (e.g., urban, rural), and teaching status. Hospitals identified general medical floors covered by hospitalists for IDR observations. Intervention: The study team conducted hospital site visits to observe the implementation of IDR. A checklist was developed to record IDR structure and processes, content, and outcomes. Data from two content expert observers were reconciled, and a consensus was attained. Main Outcome and Measures: The study measures include two IDR functions: topics discussed during IDR (changes in medical treatment, responsibilities and shared understanding of goals and expectations, anticipation of discharge date and needs, anticipating follow-up care and service needs), and effective communication. Results: Hospitals varied significantly in IDR implementation. 51.9% included the “core” team (i.e., a physician, nurse, pharmacist, and case manager/social worker), though all included a case manager or social worker. Most (81.5%) occurred before noon. Content chiefly focused on medical care (74.1 to 92.6%) with patient responsibilities and preferences being less frequently discussed (25.9 to 40.7%). Bivariate analyses revealed that afternoon rounds were more likely to include dischargeȐrelated topics, such as patient/caregiver preferences (100% vs. 27.3%, p =.003) and follow-up needs (100% vs. 36.4%, p =.010).When IDR occurred at bedside, financial resources were more often assessed (100% vs. 34.8%, p =.015) and patient's ability to obtain medication was more often anticipated (75% vs. 21.7%, p =.031).