Summary & Overview
CPT 82042: Quantitative Albumin in Non-Blood Body Fluid
CPT code 82042 represents a quantitative laboratory assay that measures albumin in a measured, timed, or random specimen when the specimen is a fluid other than blood, serum, plasma, or urine. This test is clinically important for evaluating protein content of non-blood body fluids such as pleural, peritoneal, synovial, or cerebrospinal fluid and can inform diagnoses like effusions, infections, and inflammatory or neoplastic processes. Nationally, the code matters for clinical laboratories and payers because it identifies a distinct laboratory service with implications for coverage, billing, and laboratory workflow.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of what CPT code 82042 denotes, typical clinical contexts and sites of service, and what to expect in terms of payer coverage considerations. The publication summarizes common modifiers associated with laboratory services, highlights where data is available or missing, and provides benchmark-oriented content for laboratory billing teams and revenue cycle stakeholders. The material is intended to clarify the clinical and billing scope of CPT code 82042 and to serve as a concise reference for national stakeholders.
Billing Code Overview
CPT code 82042 describes a laboratory quantitation of albumin in a measured, timed, or random specimen where the specimen is a fluid source other than blood, serum, plasma, or urine. The service reports the measured albumin concentration from a non-blood body fluid and is used when the laboratory analyst performs the quantitative assay and documents the result.
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Service type: Clinical laboratory quantitative assay
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Typical site of service: Hospital laboratory, independent clinical laboratory, or other outpatient laboratory settings where non-blood fluid specimens (for example, pleural, peritoneal, synovial, cerebrospinal fluid) are collected and analyzed
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult admitted to an inpatient ward or presenting to an outpatient specialty clinic (e.g., nephrology, infectious disease, oncology) with a suspected or known serous fluid abnormality such as pleural effusion, ascites, or cerebrospinal fluid change. A clinician orders fluid analysis including 82042 when quantitation of albumin in a non-blood fluid specimen (for example pleural, peritoneal, synovial, or cerebrospinal fluid) is required to assess protein dynamics, guide differential diagnosis (transudate vs exudate), monitor nutritional/protein status, or calculate gradient measurements (e.g., serum-ascites albumin gradient).
Workflow:
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A clinician collects a non-blood fluid specimen (random, timed, or measured) using standard sterile technique in the appropriate clinical setting (inpatient, outpatient clinic, emergency department, or procedure suite).
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The specimen is labeled and transported to the clinical laboratory with accompanying order for
82042and any other requested fluid studies. -
Laboratory personnel perform the albumin quantitation using validated methods (e.g., immunoassay) and document the numeric concentration and units in the laboratory information system.
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Results are reported to the ordering provider and integrated into the patient record to support clinical interpretation (e.g., calculation of gradients or comparison to serum albumin).
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional component of a split service (interpretation) if applicable in a lab-consult context. |
59 | Distinct procedural service | Use when 82042 is performed on a distinct anatomic site or on a separate specimen during the same encounter. |
52 | Reduced services | Use when the albumin quantitation is partially performed or limited compared with the full procedure. |
53 | Discontinued procedure | Use when specimen collection or testing is started but discontinued for patient-related or technical reasons. |
90 | Reference (outside) lab | Use when the test is performed by an outside laboratory and only reporting/transmitting occurs locally. |
91 | Repeat clinical diagnostic laboratory test | Use when a repeat quantitative albumin test is performed on the same day to obtain a subsequent result. |
TC | Technical component | Use when billing only the laboratory technical component (analytical service) without professional interpretation. |
QW | CLIA waived test | Use only if the laboratory method for 82042 is CLIA-waived and payer accepts modifier application. |
59 | Distinct procedural service | Use when multiple unrelated lab procedures are performed on separate specimens during the same encounter. |
CR | Catastrophe/disaster related | Use when the service is related to a declared catastrophe and payer requires this modifier. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207L00000X | Pathology | Clinical laboratory direction, interpretation, and oversight of albumin quantitation. |
| 207P00000X | Clinical Laboratory | Laboratory technicians and analysts performing the assay and reporting results. |
| 208D00000X | Diagnostic Radiology | Radiology may be involved when image-guided fluid aspiration precedes testing (procedure ordering/coordination). |
| 2084P0800X | Nephrology | Ordering clinician who may request fluid albumin for renal-related effusions or peritoneal fluid assessment. |
| 207K00000X | Hematology | Specialists ordering or interpreting protein studies in complex hematologic conditions. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
R09.1 | Pleurisy and pleural effusion | Pleural fluid albumin quantitation helps differentiate transudative vs exudative effusion. |
R18.8 | Other ascites | Ascitic fluid albumin measurement is used to calculate serum-ascites albumin gradient for etiology. |
G00.9 | Bacterial meningitis, unspecified | CSF albumin may be part of CSF protein evaluation in suspected meningitis. |
M00.9 | Pyogenic arthritis, unspecified | Synovial fluid albumin can be part of infection and inflammatory assessment. |
K65.9 | Peritonitis, unspecified | Peritoneal fluid analysis including albumin aids in diagnosing infectious vs noninfectious causes. |
E83.42 | Hypoalbuminemia | Quantitation in other body fluids may be relevant when assessing protein distribution and loss. |
I50.9 | Heart failure, unspecified | Pleural and ascitic fluid in heart failure patients often require albumin assessment to determine transudative processes. |
C80.1 | Malignant (primary) pleural effusion | Albumin and other fluid studies assist in characterizing malignant effusions and guiding management. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
49083 | Aspiration of peritoneal cavity (paracentesis), without imaging guidance | Specimen collection procedure that commonly precedes 82042 when ascitic fluid is sampled. |
32554 | Thoracentesis, therapeutic and diagnostic, with or without imaging guidance | Procedure to obtain pleural fluid for albumin quantitation in pleural effusion evaluation. |
62310 | Spinal puncture, lumbar, diagnostic | Procedure to obtain cerebrospinal fluid for albumin measurement when indicated. |
81002 | Urinalysis, non-automated, without microscopy | Common complementary fluid/urine studies; not a substitute but often ordered alongside fluid protein tests. |
84156 | Albumin; serum (quantitative) | Serum albumin measurement used together with 82042 to calculate gradients (e.g., serum-ascites albumin gradient). |