Summary & Overview
CPT 0484U: Macrolide Resistance Test for Mycoplasma genitalium
CPT code 0484U designates a Proprietary Laboratory Analyses (PLA) assay for detection of macrolide resistance–associated mutations in the 23S rRNA gene of Mycoplasma genitalium. This single-source molecular test from MedArbor Diagnostics and SpeeDx Inc. uses oral, rectal, or vaginal swabs to identify mutations that predict resistance to macrolide antibiotics, informing antimicrobial selection. Nationally, PLA codes like 0484U matter because they track use of manufacturer-specific diagnostics that have implications for coding, billing, and clinical decision-making.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication summarizes payer coverage patterns, coding and billing considerations for proprietary molecular tests, and clinical context around Mycoplasma genitalium macrolide resistance testing.
Readers will learn: a concise definition of the test and its clinical purpose; the typical service setting and specimen types; payer landscape and which major payers are addressed; common modifiers reported with the service (Modifiers 00, 22, 52, 53); and areas where Data not available in the input limit further detail (for example, associated taxonomies, specific ICD-10 diagnoses, and related codes). The content focuses on coding and clinical context relevant to providers, laboratories, and billing professionals working with proprietary molecular diagnostics.
Billing Code Overview
CPT code 0484U is a Proprietary Laboratory Analyses (PLA) code that reports a specific commercial molecular test for Macrolide Resistance of Mycoplasma genitalium produced by MedArbor Diagnostics and SpeeDx Inc. The assay detects mutations in the 23S rRNA gene of Mycoplasma genitalium that indicate resistance to macrolide antibiotics.
Service Type: Molecular diagnostic test (proprietary lab assay)
Typical Site of Service: Clinical laboratory; specimens are collected via oral, rectal, or vaginal swab.
Clinical & Coding Specifications
Clinical Context
A 28-year-old sexually active patient presents to a sexual health clinic with persistent urethral discharge and dysuria despite an initial course of azithromycin prescribed for suspected Mycoplasma genitalium infection. The clinician collects a swab from the urogenital site (vaginal or urethral) and, because of treatment failure, orders molecular testing for macrolide resistance mutations in the 23S rRNA gene. The specimen is sent to MedArbor Diagnostics or SpeeDx Inc. for the proprietary assay represented by 0484U. Results indicating macrolide resistance guide the clinician to select an alternative antimicrobial regimen.
Typical workflow:
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Patient evaluated in outpatient sexual health, primary care, or urgent care setting.
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Clinician collects site-appropriate swab (oral, rectal, or vaginal/urethral) and completes requisition specifying the MedArbor/SpeeDx macrolide resistance assay (
0484U). -
Specimen transported to the performing laboratory under required conditions.
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Laboratory performs nucleic acid amplification and mutation detection targeting the 23S rRNA gene; result reported as resistant or not detected for macrolide-associated mutations.
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Ordering clinician receives report and documents findings in the chart to support change in therapy and clinical management.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier. | Use when no special modifier applies; default reporting for the PLA test 0484U. |
22 | Increased procedural services. | Use when laboratory documents unusually high complexity or effort beyond typical testing (rare for automated PLA tests). |
52 | Reduced services. | Use when the test is partially performed or limited in scope compared with full procedure (e.g., inadequate specimen requiring limited testing). |
53 | Discontinued procedure. | Use when testing is started but discontinued for documented clinical or technical reasons. |
59 | Distinct procedural service. | Use if another unrelated procedure is reported on the same day and needs to be indicated as distinct. (Use cautiously with laboratory claims.) |
76 | Repeat procedure by same provider. | Use for repeat specimen testing ordered by the same provider on the same patient when repetition is required. |
77 | Repeat procedure by another provider. | Use when a different provider orders a repeat of the same test. |
90 | Reference (outside) laboratory. | Use when the performing lab is an outside/reference laboratory and reporting requirements require this modifier. |
91 | Repeat clinical diagnostic laboratory test. | Use when repeating the identical laboratory test on the same day for quality control or verification. |
QW | CLIA waived test. | Use if the specific assay is CLIA-waived (confirm assay status before applying). |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207Q00000X | Obstetrics & Gynecology | Commonly orders and collects urogenital swabs for STI testing including M. genitalium. |
208000000X | Family Medicine | Primary care providers who evaluate symptomatic patients and manage STI treatment. |
207R00000X | Infectious Disease | Specialists consulted for persistent, resistant, or complicated infections. |
208D00000X | Internal Medicine | Adult medicine providers who may order and act on resistance testing. |
363A00000X | Pathology & Laboratory Medicine | Performing or directing laboratory testing and result interpretation. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
A74.89 | Other specified chlamydial diseases | Used when clinicians document sexually transmitted infections in the differential; sometimes used when coding genital mycoplasma infections under more general categories. |
N34.1 | Urethritis, unspecified | Common presentation prompting testing for Mycoplasma genitalium and macrolide resistance. |
N76.1 | Other specified inflammation of vagina and vulva | Vaginal symptoms that may trigger STI testing including M. genitalium resistance testing. |
N76.0 | Acute vaginitis | Symptomatic vaginitis leading to diagnostic testing including pathogen identification and resistance assessment. |
A64 | Unspecified sexually transmitted infection | Used in undifferentiated STI presentations where specific pathogen not yet identified but testing for M. genitalium is performed. |
R75 | Inconclusive laboratory evidence of human immunodeficiency virus [HIV] | Represents laboratory-related coding context; included when multiple STI tests are ordered during the same encounter. |
Z11.3 | Encounter for screening for infections with a predominantly sexual mode of transmission | Screening encounters where targeted resistance testing may be ordered if initial positive M. genitalium result is obtained. |
R68.89 | Other general symptoms and signs | Non-specific symptoms such as pelvic pain or dysuria prompting STI and resistance testing. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
87480 | Infectious agent detection by nucleic acid (DNA or RNA); organisms amplified probe technique, multiple organisms or multiple probes, per specimen, each organism | May be used for the initial molecular detection of Mycoplasma genitalium when performed by other assays; often precedes or accompanies resistance testing. |
86769 | Antibody; infectious agent detection by enzyme immunoassay, multiplex, qualitative or semiquantitative; multiple infectious agents | Not specific for M. genitalium but represents other laboratory STI testing that may be ordered in the same evaluation. |
87899 | Unlisted microbiology procedure | Used when a specific molecular or resistance assay does not have an assigned CPT code; historically used prior to PLA code assignment. |
87622 | Infectious agent detection by nucleic acid (DNA or RNA); Neisseria gonorrhoeae and Chlamydia trachomatis, amplified probe technique | Frequently ordered concurrently for comprehensive STI screening when evaluating patients for urethritis or cervicitis. |
G0483 | Drug test(s), definitive, oral fluid, any number of drug classes; chromatographic, mass spectrometry, tandem mass spectrometry, etc. | May be part of broader evaluation in settings assessing treatment adherence or substance use impacting management decisions. |