Evaluation of new therapies after licensing is usually a binary decision by payers; to fund or not to fund. In the real world, many therapies fall into a gray zone of incomplete evaluation. Many clinical and economic issues in nephrology have combined to create a long list of such promising but incompletely evaluated therapies. This article focuses on the economic challenges that limit evidence generation in nephrology. Conditionally funded field evaluations such as coverage with evidence development can allow both earlier access to new treatments and rigorous evaluation. The authors propose that field evaluations will stimulate an environment that promotes pivotal renal care advances. Certainly, the evidence challenge faced by nephrology requires urgent discussions on creating conditions that catalyze and accelerate innovation, and improve patient outcomes.