Does N28.81 require prior authorization?

No, N28.81 does not require prior authorization (high confidence). Code is covered without prior authorization.

`N28.81` — Hypertrophy of kidney

ICD-10-CM

No Prior Auth Required

Code is covered without prior authorization (high confidence)

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.
This billing and coding article provides guidelines that complement Local Coverage Determination L34415 for CT of the abdomen and pelvis; consult LCD L34415 for specific coverage indications, limitations, and documentation requirements.

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).
CT abdomen is medically necessary to evaluate abdominal pain.
CT abdomen is medically necessary to evaluate known or suspected abdominal masses or fluid collections.
CT abdomen is medically necessary for evaluation of primary or metastatic malignancies in the abdomen.
CT abdomen is medically necessary to evaluate abdominal inflammatory processes.

A55336 — Billing and Coding: Retroperitoneal Ultrasound

A56421 — Billing and Coding: CT of the Abdomen and Pelvis

L34577 — Retroperitoneal Ultrasound

L34415 — CT of the Abdomen and Pelvis

Ask Verity about documentation requirements, denial risks, or coverage in your state.