Summary & Overview
CPT 82127: Targeted Single Amino Acid Detection
CPT code 82127 represents a targeted laboratory assay to determine the presence of a single amino acid in specimens such as blood, plasma, urine, amniotic fluid, or cerebrospinal fluid. This test is important nationally for screening or confirming suspected inborn errors of metabolism and for guiding clinical management when a specific amino acid abnormality is suspected. Payers of interest in national analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.
Readers will find a concise overview of clinical context, typical sites of service, and the laboratory role for this targeted amino acid detection. The publication covers how CPT code 82127 is used in practice, common settings where the test is ordered, and the types of clinical indications that prompt testing. It also summarizes payer coverage landscape, common modifiers reported with the service (input provided), and notes where input data is missing. Benchmarks, policy updates, and coding considerations relevant to laboratory billing for single-amino-acid assays are included to inform coding, claim submission, and administrative workflows at a national level.
Billing Code Overview
CPT code 82127 describes a laboratory procedure in which the analyst determines the presence of a single amino acid in a biological specimen such as blood, plasma, urine, amniotic fluid, or cerebrospinal fluid. The test commonly screens for an amino acid associated with an inborn error of metabolism and is used to detect or rule out specific metabolic disorders.
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Service type: Targeted amino acid detection in a clinical laboratory setting
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Typical site of service: Clinical laboratory; specimens collected in inpatient, outpatient, or ambulatory settings and sent to a lab for analysis
Clinical & Coding Specifications
Clinical Context
A newborn infant with feeding difficulty, vomiting, lethargy, or an abnormal newborn screen is admitted to the neonatal unit. A pediatrician orders laboratory testing to evaluate for an inborn error of metabolism. A clinical laboratory receives a blood or urine specimen and performs targeted amino acid testing to determine the presence of a single amino acid (e.g., elevated phenylalanine, methionine, or leucine) associated with disorders such as phenylketonuria, homocystinuria, or maple syrup urine disease. The specimen handling includes accessioning, aliquoting, specimen preparation, and analytic testing using techniques such as tandem mass spectrometry or amino acid analyzer. Results are reviewed by a laboratory director or clinical chemist and communicated to the pediatrician or metabolic specialist for diagnosis, treatment planning, and genetic counseling. Typical site of service is the hospital laboratory, clinical reference laboratory, or outpatient specimen collection center; specimen types include whole blood, plasma, urine, amniotic fluid, or cerebrospinal fluid.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional Component | Use when billing only the professional interpretation/reading of the laboratory analytic result, separate from the technical component. |
TC | Technical Component | Use when billing only the technical component (laboratory equipment, reagents, and personnel performing the test). |
90 | Reference (Outside) Laboratory | Use when the test is performed by an outside laboratory and results are reported by the performing lab. |
91 | Repeat Clinical Diagnostic Laboratory Test (Note: not in provided list) | Data not available in the input. |
90 | Reference (duplicate listing) | Data not available in the input. |
59 | Distinct Procedural Service (Note: not in provided list) | Data not available in the input. |
52 | Reduced Services | Use when the lab test is partially reduced or not completed as originally intended. |
53 | Discontinued Procedure | Use when specimen processing or testing was started but discontinued for clinical reasons. |
22 | Increased Procedural Services | Use when the complexity or resource use to perform the test is substantially greater than typical. |
78 | Return to Operating/Procedure Room (Note: not typical for lab) | Data not available in the input. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 182100000X | Clinical Laboratory | Laboratory scientists and clinical chemists who perform and validate amino acid testing. |
| 207Q00000X | Pediatrics | Pediatricians ordering and interpreting newborn metabolic screens and follow-up testing. |
| 207LH0000X | Medical Genetics | Medical geneticists and metabolic specialists who manage inborn errors of metabolism. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
E70.0 | Classical phenylketonuria | Elevated phenylalanine detected by single amino acid testing. |
E71.0 | Organic (fatty-acid) disorders of branched-chain amino-acid metabolism (maple syrup urine disease) | Elevated branched-chain amino acids such as leucine/isoleucine; single amino acid testing can detect a key abnormal amino acid. |
E72.1 | Hypermethioninemia | Elevated methionine identified on targeted amino acid assay. |
E72.2 | Disorders of aromatic amino-acid metabolism | Abnormal tyrosine or tryptophan levels detected by amino acid testing. |
E72.3 | Disorders of branched-chain amino-acid metabolism | Single amino acid elevations prompting diagnosis and management. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
80055 | Maternal metabolic screening (multiple analytes) | Performed during prenatal screening or newborn follow-up when expanded metabolic panels are indicated; may precede targeted single amino acid testing. |
82143 | Amino acids; quantitative, plasma (multiple amino acids) | A broader panel measuring multiple amino acids; used when a single abnormal amino acid is suspected and comprehensive profiling is needed. |
84100 | Ammonia; quantitative | Ordered alongside amino acid testing to evaluate for urea cycle disorders or severe hyperammonemia. |
36415 | Collection of venous blood by venipuncture | Common specimen collection procedure preceding the laboratory analysis for amino acid testing. |