2025 CPT code 84520
(Active) Effective Date: N/A Revision Date: N/A Laboratory - Chemistry Procedures Pathology and Laboratory Procedures > Chemistry Procedures Feed
Quantitative measurement of urea nitrogen in a blood sample.
Modifiers 59, 90, 91, 99, and others may be applicable depending on the clinical circumstances (e.g., separate procedure, repeat test, multiple tests, etc.). Refer to CPT guidelines for detailed information on modifier usage.
Medical necessity for a BUN test is established when there is clinical suspicion of kidney disease, evaluation of kidney function in chronic illnesses (e.g., diabetes, hypertension), monitoring of kidney disease progression or treatment efficacy, or assessment of dehydration. It also is used in hospital settings for general assessment.
The clinical responsibility lies with the laboratory personnel who perform the test.Physicians order the test to evaluate kidney function or in the context of assessing other conditions, such as liver disease or dehydration.
In simple words: This blood test measures the amount of urea nitrogen in your blood. Urea nitrogen is a waste product; high levels may indicate kidney problems.
This CPT code, 84520, represents a quantitative blood urea nitrogen (BUN) test.The procedure involves measuring the concentration of urea nitrogen in a patient's blood sample. This analyte, a byproduct of protein metabolism, is filtered by the kidneys and excreted in urine.Elevated BUN levels may indicate impaired kidney function, while decreased levels may suggest liver disease or other conditions. The test is performed using various methods, including spectrophotometry.
Example 1: A patient presents with symptoms suggestive of kidney disease (e.g., edema, fatigue). A BUN test is ordered to assess kidney function.Elevated BUN, along with other lab results (e.g., creatinine, GFR), confirms renal impairment., A patient with diabetes undergoes routine blood work, including a BUN test, to monitor kidney health. A moderately elevated BUN prompts further investigation to determine the extent of diabetic nephropathy., A patient hospitalized for congestive heart failure has a BUN test ordered.An elevated BUN level suggests reduced renal perfusion, worsening the prognosis and influencing treatment decisions.
** The interpretation of BUN results should always be done in conjunction with other relevant clinical data.A high BUN is non-specific, requiring additional diagnostic tests to confirm the diagnosis and establish the cause.The normal BUN range is not absolute and can vary depending on the laboratory and patient factors (age, diet, hydration).
- Revenue Code: T1H (LAB TESTS - OTHER (NON-MEDICARE FEE SCHEDULE))
- Payment Status: Active
- Modifier TC rule: Not applicable. This is a complete laboratory test.
- Specialties:Nephrology, Internal Medicine, Family Medicine, Endocrinology, Critical Care
- Place of Service:Office, Hospital (Inpatient and Outpatient), Laboratory, Urgent Care Facility, other