Summary & Overview

CPT 82139: Quantitative Analysis of Six or More Amino Acids

CPT code 82139 represents quantitative laboratory testing for six or more amino acids in a specimen such as blood, plasma, urine, or other body fluids. This multi-analyte test is used to identify abnormalities in amino acid concentrations that can indicate inborn errors of metabolism, nutritional deficiencies, or other metabolic disturbances. Nationally, accurate reporting and coding of complex laboratory panels like this matter for clinical continuity of care, utilization monitoring, and payer coverage policy development.

Key payers covered in typical analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Coverage and reimbursement practices for multi-analyte amino acid testing vary by payer and clinical indication, affecting ordering patterns and access to specialized metabolic testing.

Readers will learn the clinical context for CPT code 82139, where and how the service is typically performed, and which major payers are relevant for policy and coverage discussions. The publication provides benchmarks and policy updates where available, explains service lines and sites of service for this laboratory procedure, and situates the code within laboratory billing practices. Data not available in the input is indicated explicitly where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare82139CPTamino acid analysisclinical laboratorymetabolic testinglaboratory billingdiagnostic testing

Billing Code Overview

CPT code 82139 describes laboratory quantitative analysis for six or more amino acids performed by a laboratory analyst on a biologic specimen. The procedure measures concentrations of multiple amino acids to determine whether any values fall outside established normal limits.

Service Type: Laboratory quantitative amino acid analysis

Typical Site of Service: Clinical laboratory or hospital laboratory, using specimens such as blood, plasma, urine, or other body fluids.

Clinical & Coding Specifications

Clinical Context

A pediatric patient presents to the outpatient laboratory after referral from a metabolic specialist for evaluation of suspected inborn errors of amino acid metabolism. The child has developmental delay, poor feeding, periodic vomiting, and abnormal newborn screening or elevated plasma ammonia. A specimen of plasma or urine is collected during a clinic visit or hospital admission and sent to the clinical chemistry/molecular laboratory. The laboratory analyst performs quantitative amino acid analysis testing for six or more amino acids using methods such as high-performance liquid chromatography (HPLC) or tandem mass spectrometry to identify elevations or deficiencies that support diagnoses like phenylketonuria, maple syrup urine disease, homocystinuria, or other aminoacidopathies. Results are reported to the ordering metabolic physician; abnormal results may prompt repeat collection, confirmatory testing, nutritional or medical treatment adjustments, and genetic counseling. Typical site of service is an outpatient clinical laboratory, hospital central laboratory, or reference testing laboratory; specimens commonly include blood (plasma or serum) or urine.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	When billing only the physician interpretation or professional portion of the test if separated from technical component.
`TC`	Technical component	When billing only the laboratory technical component (equipment and technician) of the test.
`59`	Distinct procedural service	When the amino acid panel is distinct from another test or procedure on the same day and should be reported separately.
`90`	Reference laboratory	When the testing is performed by an outside/reference laboratory and billed by the ordering laboratory or provider.
`91`	Repeat clinical diagnostic lab test	When the same test is repeated on the same day to obtain a separate result or verify accuracy.
`52`	Reduced services	When the laboratory performs a reduced portion of the full test or fewer analytes than usual.
`53`	Discontinued procedure	When specimen collection or testing was started but discontinued for documented clinical reasons.
`76`	Repeat procedure by same provider	When the laboratory repeats the test after the original result due to technical issues or quality control (Note: `76` is not in input list; excluded).
`78`	Unplanned return to the operating/procedure room by same physician following initial procedure (Not typically applicable to this CPT; retained in list for completeness)
`91`	(duplicate) Repeat clinical diagnostic laboratory test	See above.

Taxonomy Code	Specialty	Notes
261QM0800X	Clinical Pathology	Clinical pathologists oversee laboratory testing and interpretation.
207RC0000X	Pediatric Medical Genetics	Specialists who order and interpret metabolic testing for inborn errors.
207L00000X	Pediatric Medicine	Pediatricians who order newborn screening follow-up and metabolic evaluations.
151VP0800X	Clinical Laboratory Director	Laboratory directors responsible for test validation and quality oversight.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`E70.0`	Phenylketonuria	PKU causes elevated phenylalanine measured on amino acid panels; testing monitors diagnosis and therapy.
`E71.1`	Maple syrup urine disease	Branched-chain amino acid elevations are diagnosed by multi-amino acid quantitative testing.
`E72.1`	Hypermethioninemia	Amino acid panel detects elevated methionine and helps identify metabolic defects.
`E72.2`	Hyperprolinemia	Quantitative amino acid analysis identifies abnormal proline levels for diagnosis and monitoring.
`E72.3`	Other amino-acidurias	General category for various aminoacidopathies detected via multi-amino acid testing.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80055`	Special chemistry tests (cholesterol, triglycerides, etc.) — panel codes vary by payer	May be ordered concurrently for metabolic workup or nutritional assessment; provides complementary metabolic data.
`82043`	Albumin; serum or plasma	Often part of basic metabolic assessment when evaluating nutritional status alongside amino acid testing.
`82150`	Amino acids; individual, quantitative (except cystine)	Used when only a single amino acid is quantified rather than a panel of six or more; may be ordered as follow-up for a specific abnormality.
`82607`	Phenylalanine; quantitative	Ordered specifically when phenylketonuria (PKU) is suspected or to monitor dietary therapy; complements multi-amino acid panels.
`83970`	Amino acids; chromatography, each amino acid (alternative methodology)	Alternate reporting or methodology codes that may be used by some laboratories to describe amino acid quantitation.
`80305`	Drug confirmation; quantitative, by mass spectrometry	Not directly the same but mass spectrometry workflows overlap; used when labs perform MS-based amino acid panels and additional confirmatory testing.