Question: Can we report 50590 for freeing a calcified ureteral stent? If so, what diagnosis would we assign with it? Connecticut Subscriber Answer: To insure correct payment for 50590 (Lithotripsy, extracorporeal shock wave) report diagnostic code N20.0 (Calculus of kidney) for stone fragmentation of the stent in the renal pelvis or N20.1 (Calculus of ureter) for stone fragmentation of the stent in the ureter. The current edition of ICD-10-CM does not include a specific diagnosis for “calcified ureteral stent.” Because the calcification could be considered a complication of genitourinary devices, an appropriate secondary diagnosis code could be T83.192A (Other mechanical complication of indwelling ureteral stent, initial encounter).