Radiology Coding Alert

Remember to use one code for abdominal and pelvic CT scans.

Regardless of whether your radiology report lists the diagnosis as a calculus or a stone in the urinary tract, you’ll use the same codes. Stones in the kidneys, bladder, or ureters can cause severe pain for patients, but with this handy refresher you can relax when a report enters your workflow.

Read on to learn the procedure and diagnosis code selection process.

Use Image Tests to Find Kidney Stones

Healthcare providers order imaging tests to find stones in the urinary tract. “The imaging exams used to evaluate calculi in the bladder, kidneys, and ureter are usually abdominal X-rays and computed tomography (CT) scans of the abdomen and pelvis,” says Taylor Berrena, COC, CPC, CPCO, CPB, CPMA, CPPM, CRC, CEMC, CFPC, CHONC, coder III at MD Anderson Cancer Center at Cooper in Yorktown, Virginia. She adds that the CT scans are “typically performed without contrast but can be done with contrast.”

Radiologists can use abdominal X-rays to locate stones in the urinary tract. Depending on the number of views captured, you’ll assign one of the following abdominal X-ray codes for the procedure:

• 74018 (Radiologic examination, abdomen; 1 view)
• 74019 (… 2 views)
• 74021 (… 3 or more views)

However, abdominal X-rays may not show all stones, which is where computed tomography (CT) scans can offer a better view. You’ll assign one of the following codes based on whether the radiologist uses contrast material or not with the procedure:

• 74176 (Computed tomography, abdomen and pelvis; without contrast material)
• 74177 (… with contrast material(s))
• 74178 (… without contrast material in one or both body regions, followed by contrast material(s) and further sections in one or both body regions)

Remember: Double-check the provider’s documentation to verify if the provider performs a CT scan on the patient’s abdomen and pelvis during the encounter. Abdominal and pelvic CT scans are reported with a single code, not separate codes for each body structure.

Choose the Correct Calculus Code

Next, you’ll need to identify the diagnosis code for the encounter. You’ll refer to the Urolithiasis code section of ICD-10-CM code set to locate kidney, bladder, and ureter calculi diagnosis codes.

“The documentation needs to include the anatomical site or organ where the calculus is located as they can manifest in several different places,” Berrena reminds.

Depending on the location of the stones, you’ll assign one of the following diagnosis codes:

• N20.0 (Calculus of kidney)
• N20.1 (Calculus of ureter)
• N20.2 (Calculus of kidney with calculus of ureter)
• N21.0 (Calculus in bladder)
• N20.9 (Urinary calculus, unspecified)

Additional synonyms: A calculus is also known as a stone, and the ICD-10-CM Alphabetic Index features entries for both calculus and stone(s). Subterms listed under both calculus and stone direct you to the correct codes in the Tabular List based on where the stones are found in the body. In fact, stone is included as part of an additional synonym for a few of the codes listed above.

For example, N20.0’s additional synonyms include renal stone and stone in kidney; N20.1’s additional synonyms include ureteric stone; and N21.0’s additional synonyms include urinary bladder stone.

Examine This Kidney Stone Encounter

Scenario: A 45-year-old patient presented to a urologist with severe lower back pain and hematuria. The urologist referred the patient to an outpatient radiology practice for an abdominal and pelvic computed tomography (CT) scan without contrast. The radiologist performed the scan and documented their findings. The impression listed a 5 mm calculus in the lower pole of the left kidney and no other significant abnormalities.

In this scenario, you’ll assign one CPT^® code and one ICD-10-CM code to report the encounter. Starting with the procedure, you’ll assign 74176 to report the abdominal and pelvis CT scan without contrast. Some coders may think you need two separate codes to report the CT scan due to the imaging of two different body structures. But remember, the CPT^® code set instructs you to use one code if CT scans of the abdomen and pelvis are performed at the same session.

Next, open the ICD-10-CM code set Alphabetic Index. Search for Calculus or Stone(s) and locate Kidney, which directs you to N20.0. You’ll then verify the code in the Tabular List.

In summary, you’ll assign 74176 and N20.0 to report this encounter.