Interventions to reduce urinary catheter use involve lists of "appropriate" indications developed from limited evidence without substantial multidisciplinary input. Implementing these lists, however, is challenging given broad interpretation of indications, such as "critical illness." To refine criteria for appropriate catheter use-defined as use in which benefits outweigh risks-the RAND/UCLA Appropriateness Method was applied. After reviewing the literature, a 15-member multidisciplinary panel of physicians, nurses, and specialists in infection prevention rated scenarios for catheter use as appropriate, inappropriate, or of uncertain appropriateness by using a standardized, multiround rating process. The appropriateness of Foley catheters, intermittent straight catheters (ISCs), and external condom catheters for hospitalized adults on medical services was assessed in 299 scenarios, including urinary retention, incontinence, wounds, urine volume measurement, urine sample collection, and comfort. The scenarios included patient-specific issues, such as difficulty turning and catheter placement challenges. The panel rated 105 Foley scenarios (43 appropriate, 48 inappropriate, 14 uncertain), 97 ISC scenarios (15 appropriate, 66 inappropriate, 16 uncertain), and 97 external catheter scenarios (30 appropriate, 51 inappropriate, 16 uncertain). The refined criteria clarify that Foley catheters are appropriate for measuring and collecting urine only when fluid status or urine cannot be assessed by other means; specify that patients in the intensive care unit (ICU) need specific medical indications for catheters because ICU location alone is not an appropriate indication; and recognize that Foley and external catheters may be pragmatically appropriate to manage urinary incontinence in select patients. These new appropriateness criteria can inform large-scale collaborative and bedside efforts to reduce inappropriate urinary catheter use.