Question: When our surgeon removes a kidney stone, what diagnosis code should we report? Texas Subscriber Answer: You should wait to get a copy of the pathology report to code the final diagnosis. You would expect the path report to include all necessary information to select a more specific code. Without that information, the best code is N20.0 (Calculus of kidney). ICD-10 provides a long list of calculi codes, and choosing the proper code depends on knowing the location of the stone within the urinary tract. You can see that you have several other codes to choose from if you have a urinary tract stone or multiple stones from different sites (including kidney) or from an unspecified site. You would choose the appropriate code from the following list: