Understanding providers' expectations and needs for medical interpreters can provide important insight into the dynamics and process of interpreter-mediated medical encounters. This is one of the first mixed-methods studies on the similarities and differences of providers' views of interpreters across five specialties (i.e., obstetrics/gynecology, emergency medicine, oncology, mental health, and nursing). The two-stage studies include interview data with 39 providers and survey data with 293 providers. We used principal component analysis to identify three components in the survey data that represent providers' views of interpreters: Patient Ally, Health Care Professionals, and Provider Proxy. We then used the interview data as exemplars to illuminate the quantitative findings. Patient Ally was the only component that reached significant differences between different specialties. Providers from different specialty areas differ significantly in their expectations on interpreters' ability (a) to assist patients outside of medical encounters and (b) to advocate for the patient. In particular, nursing professionals place more importance on these two abilities than mental health providers and oncologists. Based on our findings, we proposed three research directions necessary to advance the field of bilingual health communication: to reevaluate and reconceptualize interpreters' appropriate performances with special attention to the Patient Ally dimension, to examine the commonly held attitudes for all providers and the potential tensions within these attitudes, and to identify contextual factors that influence participants' perceptions, evaluations, and choices of interpreters and their corresponding impacts.