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Official Description

Carnitine (total and free), quantitative, each specimen

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 82379 refers to a laboratory test that quantitatively measures both total and free carnitine in a specimen. Carnitine is a vital hydrophilic amino acid derivative that plays a crucial role in energy metabolism, particularly in the breakdown of long-chain fatty acids, which are essential for mitochondrial function. This process is critical for the production of energy, as it allows the body to utilize fats for fuel. Carnitine is synthesized in the liver and kidneys and can also be obtained from dietary sources, primarily meats and dairy products. A deficiency in carnitine can lead to significant metabolic issues, as the body may struggle to convert long-chain fatty acids into energy, resulting in a lack of ketones necessary for brain function. Symptoms associated with carnitine deficiency can include hypoglycemia, muscle weakness, anemia, and complications affecting the heart and kidneys. Newborns are routinely screened for primary carnitine deficiency shortly after birth to ensure early detection and management. Additionally, secondary or acquired carnitine deficiency may arise from various conditions, including type 2 diabetes, gastrointestinal disorders, familial cardiomyopathy, renal tubule disease, chronic renal failure, and prolonged use of certain medications such as steroids, antibiotics, anticonvulsants, and total parenteral nutrition (TPN). The test requires a blood sample, which can be collected through a venipuncture or heel stick, and a urine sample, which may be obtained via voided specimen or catheterization. The analysis of serum, plasma, and urine samples is performed using tandem mass spectrometry, a highly sensitive and specific method for quantifying carnitine levels.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The CPT® Code 82379 is indicated for use in various clinical scenarios where assessment of carnitine levels is necessary. The following conditions and symptoms may warrant this laboratory test:

  • Primary Carnitine Deficiency - A genetic disorder that affects the body's ability to transport carnitine, leading to low levels in the blood.
  • Secondary Carnitine Deficiency - This can occur due to conditions such as type 2 diabetes, gastrointestinal disorders, familial cardiomyopathy, renal tubule disease, chronic renal failure, and prolonged treatment with certain medications.
  • Hypoglycemia - A condition characterized by abnormally low blood glucose levels, which may indicate an underlying metabolic issue related to carnitine.
  • Muscle Weakness - Symptoms that may suggest a deficiency in energy metabolism, potentially linked to inadequate carnitine levels.
  • Anemia - A condition that can be associated with metabolic dysfunctions, including those related to carnitine deficiency.
  • Heart and Kidney Problems - Conditions affecting these organs may necessitate evaluation of carnitine levels to assess metabolic health.

2. Procedure

The procedure for obtaining the necessary specimens for the carnitine test involves several key steps, which are outlined below:

  • Step 1: Patient Preparation - Prior to specimen collection, ensure that the patient is adequately prepared, which may include fasting or other specific instructions as per the laboratory protocol.
  • Step 2: Blood Sample Collection - A blood sample is obtained through a venipuncture or heel stick, depending on the age and condition of the patient. The site is cleaned, and a needle is inserted to draw blood into a collection tube, which is then labeled appropriately for testing.
  • Step 3: Urine Sample Collection - A urine sample is collected either through a voided specimen or catheterization, depending on the clinical situation and patient needs. The urine is collected in a sterile container to prevent contamination.
  • Step 4: Specimen Handling - Both blood and urine specimens must be handled according to laboratory standards to ensure integrity. This may involve refrigeration or immediate processing to maintain sample viability.
  • Step 5: Laboratory Analysis - The collected serum, plasma, and urine samples are analyzed using tandem mass spectrometry, a sophisticated technique that allows for precise quantification of total and free carnitine levels.

3. Post-Procedure

After the procedure, it is important to monitor the patient for any immediate adverse reactions, particularly following venipuncture. The results of the carnitine test will be interpreted by a qualified healthcare professional, who will consider the findings in conjunction with the patient's clinical history and symptoms. If carnitine deficiency is confirmed, appropriate management strategies will be discussed, which may include dietary modifications, supplementation, or further diagnostic evaluations to address underlying conditions. Patients should be informed about the importance of follow-up appointments to monitor their condition and adjust treatment as necessary.

Short Descr ASSAY OF CARNITINE
Medium Descr CARNITINE QUANTITATIVE EACH SPECIMEN
Long Descr Carnitine (total and free), quantitative, each specimen
Status Code Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 9 - Not Applicable
Multiple Procedures (51) 9 - Concept does not apply.
Bilateral Surgery (50) 9 - Concept does not apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 9 - Concept does not apply.
Co-Surgeons (62) 9 - Concept does not apply.
Team Surgery (66) 9 - Concept does not apply.
Diagnostic Imaging Family 99 - Concept Does Not Apply
CLIA Waived (QW) No
APC Status Indicator Conditionally packaged laboratory tests
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) T1H - Lab tests - other (non-Medicare fee schedule)
MUE 1
CCS Clinical Classification 233 - Laboratory - Chemistry and Hematology
90 Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.
GA Waiver of liability statement issued as required by payer policy, individual case
AY Item or service furnished to an esrd patient that is not for the treatment of esrd
91 Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient.
GZ Item or service expected to be denied as not reasonable and necessary
Date
Action
Notes
1999-01-01 Added First appearance in code book in 1999.
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