N16 — Renal tubulo-interstitial disorders in diseases classified elsewhere
ICD-10-CM
Prior Authorization
No Prior Auth Required
Code is covered without prior authorization (high confidence)
Documentation Required
- Medical records must document that the ultrasound was limited to retroperitoneal structures when billing CPT 76770/76775/76776, including images/findings demonstrating limitation to the retroperitoneum.
- If the exam was expanded to include organs outside the retroperitoneum, documentation must reflect the expansion and support billing a full or limited abdominal ultrasound (CPT 76700/76705/76706).
- Claims and documentation should follow the complementary Local Coverage Determination L34577 and any applicable LCD requirements.
- Refer to Local Coverage Determination L35026 for clinical coverage criteria, medical necessity requirements, and any required prior authorization; this article complements that LCD with billing/coding guidance.
Key Coverage Criteria
- Retroperitoneal ultrasound (CPT 76770, 76775, 76776) is covered when the exam is limited solely to retroperitoneal structures.
- A full (complete) or limited abdominal ultrasound (CPT 76700, 76705, 76706) is covered when the exam includes organs or structures outside the retroperitoneum or when primary findings involve non-retroperitoneal structures (e.g., gallbladder, liver, spleen, common bile duct).
- ICD-10-CM Codes that Support Medical Necessity — Group 1 (covered diagnoses): D56.1 - Beta thalassemia
- ICD-10-CM Codes that Support Medical Necessity — Group 1 (covered diagnoses): D57.02 - Hb-SS disease with splenic sequestration
- ICD-10-CM Codes that Support Medical Necessity — Group 1 (covered diagnoses): D57.1 - Sickle-cell disease without crisis
- ICD-10-CM Codes that Support Medical Necessity — Group 1 (covered diagnoses): D57.212 - Sickle-cell/Hb-C disease with splenic sequestration
10 Active Policies
A57198 — Billing and Coding: Serum Magnesium
A55336 — Billing and Coding: Retroperitoneal Ultrasound
A56380 — Billing and Coding: Rituximab
A56421 — Billing and Coding: CT of the Abdomen and Pelvis
A57189 — Billing and Coding: Serum Magnesium
Related Codes
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