Immigrant and refugee patients may have limited English proficiency. Effective use of professional interpreter services reduces clinically significant errors and increases the quality of care. A multitude of professional interpreter services are available, and clinicians should carefully select the preferred modality of interpretation based on the type of encounter. Ad hoc interpreters, such as family members, are least preferred because of concerns of privacy and evidence of poorer outcomes. Children less than 18 years of age should only be used as interpreters in emergency situations. Professional telephonic, video, or in-person interpreters each have distinct advantages in specific clinical situations.