How To Use CPT Code 81173

CPT 81173 describes the analysis of the full gene sequence for the androgen receptor (AR) gene. This article will cover the description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, similar codes and billing examples.

1. What is CPT Code 81173?

CPT 81173 can be used to describe the analysis of the entire gene sequence for the androgen receptor (AR) gene. This code is used when a lab analyst performs the technical steps to analyze the AR gene, using methods such as polymerase chain reaction (PCR) to amplify and detect the target genes.

2. Official Description

The official description of CPT code 81173 is: ‘AR (androgen receptor) (eg, spinal and bulbar muscular atrophy, Kennedy disease, X chromosome inactivation) gene analysis; full gene sequence.’

3. Procedure

1. The lab analyst performs the technical steps to analyze the entire gene sequence of the androgen receptor (AR) gene.
2. This involves extracting nucleic acids from a specimen, such as blood, using methods like cell lysis and digestion.
3. The lab analyst then amplifies and stabilizes the quantity of nucleic acid for analysis using techniques like polymerase chain reaction (PCR).
4. The target genes, specifically the AR gene, are detected and analyzed.

4. Qualifying circumstances

CPT 81173 is commonly ordered by clinicians to aid in the diagnosis of conditions such as Kennedy disease (spinobulbar muscular atrophy) and X chromosome inactivation. Kennedy disease is an X-linked condition characterized by muscle weakness and androgen insensitivity. X chromosome inactivation is a neurodegenerative disorder that affects males and is expressed in the maternal AR gene.

5. When to use CPT code 81173

CPT code 81173 should be used when there is a need to analyze the full gene sequence of the androgen receptor (AR) gene. It is appropriate to bill this code when the lab analyst performs the technical steps to analyze the entire gene sequence using methods like PCR. This code should not be used for testing specific alleles or known familial variants of the AR gene.

6. Documentation requirements

To support a claim for CPT 81173, documentation should include:

• Reason for ordering the test and the specific condition being evaluated
• Details of the technical steps performed, including specimen type, extraction methods, and amplification techniques
• Date and time of the analysis
• Results of the analysis, specifically the findings related to the full gene sequence of the AR gene
• Signature of the lab analyst performing the analysis

7. Billing guidelines

When billing for CPT 81173, ensure that the analysis of the full gene sequence of the AR gene is performed by a lab analyst. It is important to distinguish this code from other codes related to the AR gene, such as characterization of alleles (CPT 81204) and known familial variants (CPT 81174). Additionally, if the ordering clinician requests physician interpretation of the test and the pathologist provides an interpretation and report, you may report additional codes such as G0452 with modifier 26.

8. Historical information

CPT 81173 was added to the Current Procedural Terminology system on January 1, 2019. There have been no updates to the code since its addition.

9. Examples

1. A lab analyst performs the analysis of the full gene sequence of the androgen receptor (AR) gene for a patient suspected of having Kennedy disease.
2. The AR gene is analyzed in a patient’s blood sample to determine X chromosome inactivation.
3. A lab analyst uses PCR to amplify and detect the target genes in the full gene sequence of the AR gene for a patient with suspected androgen insensitivity.
4. The entire gene sequence of the AR gene is analyzed to identify any mutations or abnormalities in a patient with symptoms of spinal and bulbar muscular atrophy.
5. A lab analyst performs the technical steps to analyze the full gene sequence of the AR gene for research purposes.