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Official Description

Mitochondrial antibody (eg, M2), each

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86381 refers to the testing for mitochondrial antibodies, specifically the M2 type, which are crucial in the diagnosis of primary biliary cholangitis (PBC). This autoimmune condition is characterized by the gradual destruction of the bile ducts within the liver, resulting from chronic inflammation. Over time, this destruction leads to irreversible scarring of liver tissue, ultimately culminating in liver failure if left untreated. The presence of antimitochondrial M2 antibodies (AMAs) in the blood serves as a significant indicator of PBC, with over 90% of patients diagnosed with this condition testing positive for these antibodies. The test is particularly relevant for individuals who exhibit symptoms such as chronic itching (pruritus), fatigue, abdominal pain, or unexplained biochemical evidence of cholestasis, which is often indicated by elevated alkaline phosphatase (ALP) levels. Furthermore, certain risk factors, including having an autoimmune disorder, a family history of PBC, the use of nail polish, hormone replacement therapy, and cigarette smoking, can increase the likelihood of developing this disease. The testing process typically involves obtaining a venous blood sample, which is then analyzed for the presence of AMAs using various methods, including indirect immunofluorescence, immunoblotting, enzyme immunoassays, luminex bead assays, and enzyme inhibition assays. The reliability of a positive AMA test result, particularly at a titer greater than 1:40, makes it a critical component in the diagnostic evaluation of patients suspected of having PBC.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The mitochondrial antibody (M2) test, represented by CPT® Code 86381, is indicated for the following conditions and symptoms:

  • Primary Biliary Cholangitis (PBC) - This autoimmune disease is characterized by the progressive destruction of the bile ducts in the liver, leading to chronic inflammation and potential liver failure.
  • Symptoms of PBC - Patients presenting with chronic pruritus (itching), fatigue, abdominal pain, or unexplained biochemical evidence of cholestasis, particularly with elevated alkaline phosphatase (ALP) levels, may require this test for diagnosis.
  • Risk Factors - Individuals with a family history of PBC, those with other autoimmune disorders, and patients who use nail polish, undergo hormone replacement therapy, or smoke cigarettes are at an increased risk for developing PBC and may be tested for AMAs.

2. Procedure

The procedure for testing mitochondrial antibodies (M2) involves several key steps, which are outlined as follows:

  • Step 1: Patient Preparation - Prior to the test, the patient may be advised to avoid certain medications or substances that could interfere with the results, although specific instructions should be provided by the healthcare provider.
  • Step 2: Blood Sample Collection - A healthcare professional will obtain a venous blood sample from the patient. This is typically done using a needle to draw blood from a vein in the arm, ensuring that the sample is collected in a manner that minimizes contamination and preserves the integrity of the specimen.
  • Step 3: Laboratory Analysis - The collected serum is then sent to a laboratory for analysis. The testing for antimitochondrial M2 antibodies is usually performed using indirect immunofluorescence, but other methods such as immunoblotting, enzyme immunoassays, luminex bead assays, and enzyme inhibition assays may also be utilized depending on the laboratory's capabilities and protocols.
  • Step 4: Result Interpretation - The laboratory will analyze the serum for the presence of AMAs, with a positive result (titer >1:40) being a strong indicator of primary biliary cholangitis. The results will be reported back to the healthcare provider for further evaluation and management of the patient's condition.

3. Post-Procedure

After the mitochondrial antibody test is completed, patients may be advised to resume normal activities immediately, as there are typically no significant post-procedure restrictions. The healthcare provider will discuss the results with the patient once they are available, which may take several days. If the test result is positive, further diagnostic evaluations or treatment options may be considered based on the patient's overall clinical picture and symptoms. It is important for patients to follow up with their healthcare provider to understand the implications of the test results and to discuss any necessary next steps in their care.

Short Descr MITOCHONDRIAL ANTIBODY EACH
Medium Descr MITOCHONDRIAL ANTIBODY EACH
Long Descr Mitochondrial antibody (eg, M2), each
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) none
MUE 4
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.
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.
Q4 Service for ordering/referring physician qualifies as a service exemption
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
GA Waiver of liability statement issued as required by payer policy, individual case
GW Service not related to the hospice patient's terminal condition
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
GZ Item or service expected to be denied as not reasonable and necessary
PO Excepted service provided at an off-campus, outpatient, provider-based department of a hospital
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Q3 Live kidney donor surgery and related services
Date
Action
Notes
2022-01-01 Added Code added
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Description
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