Extracorporeal Shock Wave Lithotripsy (ESWL) — Clinical Review Criteria
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Clinical review criteria defining medical necessity and level-of-care guidance for ESWL in adult members of Kaiser Permanente Washington (Medicare and non‑Medicare), covering ureteral and renal stones.
MPC approved to adopt criteria for Extracorporeal Shock Wave Lithotripsy (ESWL) for Medicare and non‑Medicare members; requires 60‑day notice, effective 02/01/2026.
Medical Necessity — Covered Indications & Contraindications
Ureteral Stones
Covered when ALL of the following are met
Ureteral stones
- Medical expulsive therapy for 4-6 mm stones: Patients with stones 4-6 mm in size should have completed medical expulsive therapy with at least 2 weeks of an alpha blocker unless not tolerated or contraindicated.
- Medical expulsive therapy for ≤4 mm stones: Patients with stones ≤4 mm should have completed medical expulsive therapy with at least 4 weeks of an alpha blocker unless not tolerated or contraindicated.
- Modality preference for mid to distal ureter: For stones in the mid to distal ureter, ureteroscopy (URS) is preferred; requests for ESWL will only be considered when a rationale is provided explaining why URS is not being pursued.
- Radiopacity: Stone must be visible on plain radiograph (radiopaque).
Renal Stones
Covered when ALL of the following are met
Renal stones
- Total stone burden or candidacy: Total stone burden is less than 20 mm, or the patient is not a candidate for percutaneous nephrolithotomy (PCNL) or ureteroscopy (URS).<20 mm
The following are contraindications to Extracorporeal Shock Wave Lithotripsy (ESWL) for ureteral or renal stones. ESWL is contraindicated for suspected cystine or uric acid stones (ureteroscopy is recommended in these cases), in the presence of an untreated active urinary tract infection, for a single lower pole stone >10 mm unless percutaneous nephrolithotomy (PCNL) and/or ureteroscopy (URS) have failed or are contraindicated, and when there has been a prior ESWL that failed to treat the current stone.
Retreatment with ESWL is discouraged because ESWL has a higher retreatment rate compared with cystourethroscopy. Retreatment within 12 months is not recommended and is considered a relative contraindication; in such cases definitive therapy with cystourethroscopy is recommended. Requests for repeat ESWL should include rationale why definitive endoscopic therapy (cystourethroscopy/URS) is not being pursued, and be evaluated in the context of other contraindications (for example prior failed ESWL or stone compositions such as cystine or uric acid).
Billing Codes and Stone Burden Thresholds
| 50590 | Lithotripsy, extracorporeal shock wave |
Prior Authorization, Documentation & Operational Requirements
Prior Authorization Required
Prior authorization is required. Requests must demonstrate that the member meets medical necessity per the policy criteria (e.g., stone size, location, and prior therapy). Include applicable procedure codes on the request (e.g., CPT/HCPCS for ESWL) and indicate whether the request is for ureteral or renal stones.
- Prior authorization required before scheduling ESWL
- Include applicable CPT/HCPCS codes (e.g., 50590) on the authorization request
Medical Expulsive Therapy Requirement
Before ESWL is approved for ureteral stones, members must have completed medical expulsive therapy (alpha‑blocker) for the required duration unless not tolerated or contraindicated: stones 4–6 mm = at least 2 weeks; stones ≤4 mm = at least 4 weeks. For mid to distal ureteral stones, ureteroscopy (URS) is the preferred procedure; ESWL requests must include rationale explaining why URS is not being pursued.
- Stones 4–6 mm: ≥2 weeks of alpha‑blocker unless contraindicated
- Stones ≤4 mm: ≥4 weeks of alpha‑blocker unless contraindicated
- For mid/distal ureter stones, submit rationale if ESWL chosen instead of URS
Required Supporting Documentation
Submit supporting clinical documentation to demonstrate medical necessity. At minimum, provide the last 6 months of clinical notes from the requesting provider and/or specialist. Documentation should include stone size, location, imaging results (radiopacity on plain radiograph when applicable), prior therapies, and rationale if alternative procedures (e.g., URS, PCNL) are not appropriate.
- Last 6 months of clinical notes from requesting provider and/or specialist
- Imaging reports showing stone size, location, and radiopacity
- Documentation of prior therapies and rationale if URS/PCNL not pursued
Denial Triggers / Relative Contraindications
Certain conditions are denial triggers or relative contraindications for ESWL. Requests meeting these criteria are likely to be denied or returned for clarification unless compelling justification and documentation are provided.
- Suspected cystine or uric acid stones — URS is recommended instead
- Untreated active urinary tract infection — treat and document resolution before ESWL
- Single lower pole renal stone >10 mm (unless PCNL/URS have failed or are contraindicated)
- Prior failed ESWL for the current stone
- Retreatment within 12 months is generally not recommended and is a relative contraindication; consider definitive cystourethroscopy instead
Clinical Background
Extracorporeal Shock Wave Lithotripsy (ESWL) uses externally generated pulsed energy to fragment urinary stones to facilitate clearance of stone fragments via urinary voiding. ESWL is noninvasive but is contraindicated in certain clinical situations, including pregnancy, uncontrolled hypertension, untreated coagulopathy or urinary tract infection, and when patient anatomy, body habitus, distal obstruction, or stone composition (for example suspected cystine or uric acid stones) precludes safe targeting or effective fragmentation.
Key Definitions
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