Urology Coding Alert

Question: How should we code repeat extracorporeal shock wave lithotripsy (ESWL) treatments? Does it make a difference if the second treatment is for a stone on the contralateral side?

New Jersey Subscriber

Answer: Kidney stones tend to recur, so patients who require ESWL may need repeat treatments. If the patient has one such procedure, you may need modifier -58 (Staged or related procedure or service by the same physician during the postoperative period) appended to the second to ensure proper payment.

If a stone is large and incompletely fragmented during the initial treatment and a repeat ESWL is planned and documented in the first procedure's dictation, you should report 50590-58 (Lithotripsy, extracorporeal shock wave) for the second. Payment will not be reduced for this prospectively planned repeat treatment.

If a stone recurs after an ESWL treatment most often months or years beyond the procedure's 90-day global period you should code 50590 without modifiers.

When ESWL fragments a stone completely, passage of all fragments is expected. However, several weeks later, within the global period, a ureteral fragment is noted and requires a repeat treatment. The urologist did not anticipate this event, so you should not use modifier -58. Instead, you should report the second ESWL as 50590-78 (Return to the operating room for a related procedure during the postoperative period), indicating the return to the operating room for treatment of a complication. Payment will include only the intraoperative portion of the global fee approximately 80 percent.

If a patient has bilateral renal calculi and you indicate preoperatively that this will be a staged procedure, you should code the first ESWL as 50590 and the second treatment as 50590-58. In addition, you should append modifier -79 (Unrelated procedure or service by the same physician during the postoperative period) and support the procedures' medical necessity with 592.0 (Calculus of kidney).

When a patient has a ureteral stone on one side and a renal calculus on the opposite, the urologist may perform ESWL on different days. In this instance, you should report 50590 with 592.1 (Calculus of ureter) for the ureteral stone for the service on day one, and 50590-79 with 592.0 for the services on day 21, for example. Modifier -79 normally mandates a different diagnosis in the absence of the -LT (Left side) and -RT (Right side) modifiers and indicates a surgical procedure unrelated to a previously reported procedure.

If a patient has bilateral renal calculi and, on the rare occasion, has a bilateral ESWL during one encounter, you should report 50590-50. Modifier -50 indicates a bilateral procedure. For Medicare, use one line on the CMS 1500 form. For commercial carriers, report 50590-LT, and 50590-RT and modifier -50.