Purpose: To define important elements of a structured radiology report of a CT or MRI performed to evaluate an indeterminate renal mass. Methods: IRB approval was waived for this multi-site prospective quality improvement study. A 35-question survey investigating elements of a CT or MRI report describing a renal mass was created through an iterative process by the Society of Abdominal Radiology Disease-Focused Panel on renal cell carcinoma. Surveys were distributed to consenting abdominal radiologists and urologists at nine academic institutions. Consensus within and between specialties was defined as ≥70% agreement. Respondent rates were compared with Chi Square test. Results: The response rate was 68% (117/171; 55% [39/71] urologists, 78% [78/100] radiologists). Inter-specialty consensus was that the following were essential: mass size with comparison to prior imaging, mass type (cystic vs. solid), presence of fat, presence of enhancement, and radiologic stage. Urologists were more likely to prefer the Nephrometry score (75% [27/36] vs. 22% [17/76], p < 0.0001), quantitative reporting of enhancement on CT (85% [32/38] vs. 46% [36/77], p < 0.0001), and mass position with respect to the renal polar lines (67% [24/36] vs. 36% [27/76], p = 0.002). There was inter-specialty consensus that the Bosniak classification for cystic masses was preferred. Most urologists (60% [21/35]) preferred management recommendations be omitted for solid masses or Bosniak III–IV cystic masses. Conclusions: Important elements to include in a CT or MRI report of an indeterminate renal mass are critical diagnostic features, the Bosniak classification if relevant, and the most likely specific diagnosis when feasible; including management recommendations is controversial.