Have you ever wondered why a simple procedure, such as measuring residual urine in the bladder, can feel so complex when it comes to billing? Well, you are not alone. Many billers experience the same issue. CPT code 51798 is one of the most frequently performed urologic procedures. However, it is also among the most commonly denied.
That is why our billing experts at MediBillMD have created this detailed guide on code 51798. Unlike other urology codes, 51798 has special billing requirements, and we will discuss them. So, let’s start.
CPT Code 51798 – Description
Let’s start with a simple description. CPT code 51798 is defined as:
“Measurement of post-voiding residual urine and/or bladder capacity by ultrasound, non-imaging.”
Let’s break this down in simple terms.
CPT code 51798 is used to bill a urodynamic procedure that measures the amount of residual urine in the bladder after a patient has voided (passed urine). The procedure is performed using a handheld and battery-powered ultrasound device. It’s a quick, non-invasive test that provides valuable data on bladder function, helping diagnose conditions related to incomplete emptying.
It is a non-imaging ultrasound, distinguishing it from traditional diagnostic ultrasound procedures (sonography) that produce stored images. During the procedure, the technician places the scanner over the suprapubic area to get the measurements. The device’s built-in software automatically calculates the post-void urine residue volume and displays it on the screen.
Scenarios Where CPT Code 51798 is Applicable
Isn’t it frustrating when a claim gets denied because you did not use the right CPT code for a given situation? Knowing when to apply CPT code 51798 can prevent that. The following are some real-world scenarios in which this code can be used.
Bladder-Neck Obstruction
Let’s take an example of a 65-year-old male patient experiencing difficulty in urination, a weak urine stream, and frequent urination. He has a history of prostate enlargement. He visits a urologist for treatment. The physician suspects bladder-neck obstruction (ICD-10 code N32.0), causing urinary retention.
To assess bladder function, a post-void residual urine test is ordered using an ultrasound. The test measures urine left in the bladder after voiding, confirming significant retention. CPT code 51798 is used to report the ultrasound measurement of post-void residual urine
Vesical Tenesmus
Imagine a 55-year-old female patient reporting painful urges to urinate with minimal output and lower abdominal discomfort. She had urinary tract infections before. The physician suspects vesical tenesmus (ICD-10 code R30.1), which causes incomplete bladder emptying.
A non-imaging ultrasound is performed to measure residual urine volume after voiding. The results show elevated residual urine, supporting the diagnosis. CPT code 51798 is used to report the ultrasound measurement.
Applicable Modifiers for CPT Code 51798
Modifier 59 is typically appended to CPT code 51798 for coding specificity. Let us explain.
Modifier 59
This modifier indicates a distinct procedural service. So, you can append it to code 51798 when the ultrasound is performed separately from another procedure performed on the same patient on the same day. It helps you unbundle the two services and seek separate reimbursements.
CPT Code 51798 – Billing & Reimbursement Guidelines
Oftentimes, overlooking simple billing guidelines leads to claim denials and lost revenue. That is why we have provided the most essential tips below that you must consider while filing claims for CPT code 51798.
Provide Supporting Documentation
Like all claims, 51798 claims must be backed by comprehensive documentation to justify medical necessity. According to the CMS guidelines, the following documents are required for CPT code 51798:
- The assessment of the patient by the ordering provider with a valid ICD-10 diagnosis
- Test results
- Relevant medical history
- Signed and dated office visit record/operative report
Follow the Frequency Limitations
Medicare imposes strict frequency limitations on CPT 51798, allowing only one procedure per day per patient. Services exceeding this parameter are considered not medically necessary and will be denied.
Additionally, place of service restrictions significantly impact reimbursement for CPT 51798. Medicare will not reimburse this procedure when performed in place of service 21 (inpatient hospital) or 23 (emergency room).
Another cause of 51798 denials is performing both catheterization and ultrasound in the same session. Please note that using both ultrasound and catheterization during the same session to determine post-void residual is not medically necessary and may result in claim denials.
Confirm the Reimbursement Rates
CPT code 51798 is technical-only. This means that it is only performed by technical staff and does not include interpretation or any other service provided by a physician. This is also evident by the zero work RVUs. This explains the relatively low payment rates compared to physician-performed procedures.
However, Medicare’s national average reimbursement rate for code 51798 in non-facility settings is $11.32. You can check the exact amount for your MAC locality using the PFS Lookup Tool.
Wrapping Up
With that, we have reached the end of this guide. We understand this is a lot of information to retain. So, let’s recap.
CPT code 51798 is used for billing a urodynamic test that measures the amount of residual urine in the bladder after a patient has voided. For proper reimbursement, you must ensure the code’s correct usage and provide detailed documentation with your claims.
However, in case you find it challenging to handle medical coding and billing in-house, we recommend exploring professional urology billing services offered by third-party billing companies.
