Question: The urologist used a silver nitrate instillation into the patient’s bladder because of diagnoses for urinary frequency and chronic cystitis. This is not an instillation of an anticarcinogen. What CPT® code should be used? Nebraska Subscriber Answer: The correct code is 51700 (Bladder irrigation, simple, lavage and/or instillation). If this had been performed for provision of chemotherapeutic agents, you would report both the specific service in addition to code(s) for the specific substance(s) or drug(s) provided. Remember: Bladder irrigation and instillation are used to deliver medication directly into the bladder via a catheter. These medications are usually anti-inflammatory agents used to treat infection or conditions like interstitial cystitis. The physician uses a catheter to fill the patient’s bladder with a therapeutic solution — often called a “bladder cocktail.” This cocktail is made up of various protective and healing agents. The cocktail stays in the bladder for varying amounts of time, depending on the patient’s tolerance to the drugs. The bladder is then drained through the catheter. Irrigation, another common procedure, involves passing a saline or therapeutic solution quickly in and out of the bladder. This flushes the bladder of clots or debris.