CPT 82485: Chondroitin B Sulfate Quantitative Assay

Headline: CPT code 82485: Laboratory Assay for Chondroitin B Sulfate

Lead: CPT code 82485 designates a quantitative laboratory assay for chondroitin B sulfate, a glycosaminoglycan found in cartilage. The test supports biochemical evaluation of cartilage-related disorders and can inform diagnostic and monitoring strategies in musculoskeletal and metabolic conditions.

CPT code 82485 matters nationally because it covers a specialized biochemical assay used in diagnostic workflows for patients with suspected cartilage degradation or metabolic cartilage disorders. As a pathology/laboratory service, this code affects clinical laboratories, hospital labs, and payers that reimburse specialized testing.

Key payers covered in this publication include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The analysis addresses how coverage and reimbursement considerations for specialized lab assays intersect with clinical utilization and coding practice.

Readers will learn the clinical context of the assay, the typical settings where the service is performed, and the practical billing considerations tied to CPT code 82485. The publication provides benchmark-oriented content, policy and coding context, and a concise clinical summary to support coding accuracy and administrative planning. Data not available in the input is noted where applicable.

Billing Code Overview

CPT code 82485 represents a laboratory measurement of chondroitin B sulfate concentration in a patient specimen. Chondroitin sulfate is a component of cartilage and other connective tissues and is measured to assess biochemical aspects of joint and cartilage metabolism.

Service Type: Laboratory test — quantitative biochemical assay

Typical Site of Service: Clinical laboratory or hospital laboratory

Clinical Context

A middle-aged patient with progressive knee pain and swelling is evaluated for degenerative joint disease. The clinician orders laboratory assessment of cartilage components to investigate biochemical markers of cartilage turnover and to support diagnosis or research evaluation. A blood or synovial fluid specimen is collected in the outpatient clinic or ambulatory lab and sent to the clinical chemistry laboratory. A laboratory analyst performs an assay to measure the level of chondroitin B sulfate using immunoassay or chromatographic methods. Results are routed to the ordering provider and incorporated into clinical documentation to support management decisions such as conservative therapy, referral to orthopedics, or enrollment in a clinical study of osteoarthritis biomarkers.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	When billing only the professional interpretation or analytical expertise separate from the technical lab processing.
`TC`	Technical component	When billing only the laboratory technical component (instrumentation, reagents, technician time).

Taxonomy Code	Specialty	Notes
2085R0200X	Clinical Pathology	Physicians directing clinical chemistry laboratories and interpreting complex assays.
2085P0206X	Clinical Laboratory Scientist	Professionals performing laboratory analyses including biochemical assays.
261QM0800X	Orthopedic Surgery	Ordering providers who request cartilage biomarker testing for musculoskeletal diagnoses.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`M17.9`	Osteoarthritis of knee, unspecified	Common indication for cartilage biomarker testing to assess joint degeneration.
`M19.90`	Osteoarthritis, unspecified site	General osteoarthritis evaluation where cartilage matrix markers may be informative.
`M25.56`	Pain in knee	Symptom prompting evaluation including synovial fluid or biochemical analysis.
`M12.5`	Traumatic arthropathy	Post-traumatic cartilage damage assessment may include glycosaminoglycan levels.
`M00.9`	Pyogenic arthritis, unspecified	When infection is suspected, synovial testing including biochemical and microbiology is performed.
`R52`	Pain, not elsewhere classified	Non-specific pain evaluations sometimes include adjunctive laboratory biomarkers.
`M75.10`	Unspecified rotator cuff tear or rupture of shoulder	Example of other joint pathology where cartilage biomarkers could be applied.
`M23.9`	Internal derangement of knee, unspecified	Structural joint pathology assessment may include biochemical markers of cartilage turnover.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`83520`	Assay of protein, total; urine or other body fluid	May be performed alongside when evaluating synovial fluid biochemistry.
`83912`	Assay of glycosaminoglycans (e.g., chondroitin sulfates)	Related biochemical assay for cartilage matrix components; may be ordered in the same panel.
`83036`	Hemoglobin; glycosylated (A1C)	Unrelated metabolic screen sometimes ordered concurrently in comprehensive evaluations.
`87070`	Culture, bacterial; quantitative colony count	Performed when synovial infection is part of the differential and fluid is submitted.
`81002`	Urinalysis, non-automated, without microscopy	Example of routine laboratory studies that may be ordered during the same encounter for baseline data.

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Summary & Overview