Summary & Overview

CPT 50391: Therapeutic Instillation into Renal Pelvis or Ureter

CPT code 50391 denotes the instillation of a therapeutic agent—such as an anticarcinogenic or antifungal medication—directly into the renal pelvis and/or ureter via a pre-existing nephrostomy, pyelostomy, or ureterostomy tube. This targeted local therapy is used in select urologic and oncologic contexts to deliver medication to the upper urinary tract and can reduce systemic exposure while concentrating treatment at the disease site. Nationally, the code matters for hospitals, interventional radiology services, and urology practices that manage patients with urinary tract stomas or nephrostomy access.

Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical purpose and service setting, common billing modifiers and practical billing context, and pointers to related procedural and diagnosis coding where available. The publication summarizes typical sites of service and the procedural intent, clarifies common modifier usage patterns, and highlights areas where payers commonly require documentation to support the medical necessity of local instillation therapies. Data not available in the input will be noted explicitly in relevant sections.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare50391CPTurologynephrostomytherapeutic-instillationinterventional-radiologyrenal-pelvisureter

Billing Code Overview

CPT code 50391 describes injection of a therapeutic agent (for example, an anticarcinogenic or antifungal medication) into the renal pelvis and/or ureter through a previously established nephrostomy, pyelostomy, or ureterostomy tube. This procedure is a targeted, local instillation of medication into the upper urinary collecting system.

Service type: Therapeutic instillation into renal pelvis and/or ureter via existing ostomy or nephrostomy tube
Typical site of service: Procedures are typically performed in inpatient or outpatient hospital procedural areas, interventional radiology suites, or specialized urology clinics where patients have an existing nephrostomy, pyelostomy, or ureterostomy tube

Clinical & Coding Specifications

Clinical Context

A 68-year-old male with a long-standing percutaneous nephrostomy tube placed for management of an infected, obstructed kidney from transitional cell carcinoma returns to interventional radiology/urology for instillation of a chemotherapeutic agent into the renal collecting system. The procedure is performed through the existing nephrostomy tube under sterile conditions. The provider confirms tube patency and correct positioning by aspirating urine and, if indicated, injecting a small amount of contrast under fluoroscopy. After confirming access to the renal pelvis and/or proximal ureter, the provider injects the prescribed therapeutic agent (for example, an anticarcinogenic intrapelvic instillation) slowly through the nephrostomy tube. The patient is monitored for pain, signs of systemic absorption/allergic reaction, bleeding, or extravasation. Typical workflow includes verification of indications and consent, review of prior imaging and recent labs (including coagulation status), analgesia or conscious sedation as required, procedure documentation of the agent, dose, volume, dwell time if applicable, and tube clamping or drainage instructions upon completion. Expected sites of service are interventional radiology suite, ambulatory surgery center, or hospital inpatient setting when the nephrostomy/pyelostomy/ureterostomy tube is already in place and the instillation is performed through that preexisting access.

Coding Specifications

Modifier	Description	When to Use
`11`	Normal, standard performance of the service	Use when the procedure is performed as expected without complications or unusual circumstances.

Taxonomy Code	Specialty	Notes
363LF0000X	Urology	Urologists commonly perform intrapelvic instillations via ureterostomy or nephrostomy access.
363LP0800X	Interventional Radiology	Interventional radiologists frequently manage and use percutaneous nephrostomy access for instillations.
208000000X	General Surgery	General surgeons with endourology training may perform tube-based instillations in some settings.
207P00000X	Family Medicine	In limited outpatient settings, family physicians with procedures privileges may be involved in ongoing tube care and instillation coordination.

ICD-10 Code	Description	Clinical Relevance
`C64.9`	Malignant neoplasm of kidney, unspecified	Renal pelvic/ureteral tumors may be treated with topical intrapelvic chemotherapeutic instillation via nephrostomy.
`C65.9`	Malignant neoplasm of renal pelvis, unspecified	Primary indication for anticarcinogenic instillation into the renal pelvis/ureter.
`N13.6`	Pyonephrosis	Instillation of antifungal or antimicrobial agents may be used adjunctively through nephrostomy in infectious obstruction.
`N13.8`	Other obstructive and reflux uropathy	Obstruction with infected collecting system may require therapeutic instillation and drainage management.
`T81.89XA`	Other complications of procedures, initial encounter	Used if there are documented complications related to prior catheter placement or instillation requiring coding.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`50392`	Injection procedure for renal pelvis and/or ureter via a newly placed nephrostomy, pyelostomy, or ureterostomy tube (new tube placement with instillation)	May be used when the instillation is performed at the time of initial placement of the drainage tube, rather than through a preexisting tube.
`50380`	Nephrostomy, percutaneous, with insertion of indwelling catheter (e.g., placement of nephrostomy tube)	Commonly performed before or separately from an instillation if tube placement is required prior to delivering therapeutic agent.
`74450`	Radiologic supervision and interpretation, pyelogram (injection of contrast through nephrostomy)	Often performed adjunctively to document catheter position and contrast flow prior to or during instillation under fluoroscopic guidance.
`76937`	Ultrasound guidance for vascular access and/or therapeutic injection requiring evaluation of position (if ultrasound used to confirm access)	May be billed when ultrasound guidance is used to confirm tube position or guide instillation in some clinical workflows.
`90472`	Immunization administration by intramuscular or subcutaneous route (therapeutic instillation codes vary)	Not directly related but listed in some coding algorithms for injection administration services; use caution and follow payer guidance.

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