82140 Assay of ammonia
Also known as: ammonia level, plasma ammonia, hepatic encephalopathy test
Enzymatic or ion-selective electrode measurement of ammonia concentration in plasma or serum to evaluate hepatic function and urea cycle disorders.
In Plain Language
liver function test; confusion from liver disease test; ammonia level check
Clinical Context
Elevated in cirrhosis with hepatic encephalopathy and urea cycle defects; used to assess severity and treatment response.
RVU Information
CPT 82140 does not have a physician work RVU assigned by CMS. Reimbursement for this code is determined by payer-specific fee schedules.
Billing & Documentation
Lab and pathology codes require an order from the treating provider with clinical indication. For molecular pathology and genetic testing, document the specific analytes tested and clinical rationale.
How This Code Compares
This code has a work RVU of 0.00, meaning it does not have a physician work component assigned by CMS. In the Pathology & Lab category, 94% of codes share this characteristic.
Specialties
Frequently Asked Questions
What is CPT code 82140?
CPT 82140 (Assay of ammonia) is a Pathology & Lab code. Enzymatic or ion-selective electrode measurement of ammonia concentration in plasma or serum to evaluate hepatic function and urea cycle disorders.
Who uses CPT code 82140?
CPT 82140 is used by Pathology, Hepatology, Neurology. Elevated in cirrhosis with hepatic encephalopathy and urea cycle defects; used to assess severity and treatment response.
When is CPT 82140 used?
Elevated in cirrhosis with hepatic encephalopathy and urea cycle defects; used to assess severity and treatment response.
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CPT® is a registered trademark of the American Medical Association. Data sourced from CMS Physician Fee Schedule RVU26A. Descriptions, synonyms, and clinical context are original content by RVU Edge.