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Official Description

Endomysial antibody (EMA), each immunoglobulin (Ig) class

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86231 refers to the laboratory test for endomysial antibodies (EMA), which are specific autoantibodies produced in response to gluten, a protein found in wheat, barley, rye, and oats. This test is primarily utilized in the diagnosis of celiac disease, also known as celiac sprue, a condition characterized by an abnormal immune reaction to gluten that leads to damage of the small intestine's villi. The presence of these antibodies indicates an immune response that can result in malabsorption of essential nutrients, leading to various gastrointestinal and systemic symptoms. Common symptoms associated with celiac disease include recurring abdominal pain, bloating, and changes in bowel habits such as chronic diarrhea or constipation, often accompanied by pale, foul-smelling stools. Patients may also experience weight loss and iron deficiency anemia due to nutrient malabsorption. The EMA test specifically targets immunoglobulin A (IgA) antibodies, which are highly specific for celiac disease. In cases where patients have IgA deficiency, testing for immunoglobulin G (IgG) antibodies may be performed as an alternative. The test is conducted using a venous blood sample, and the serum is analyzed through the indirect immunofluorescent antibody (IFA) technique, providing a qualitative result. It is important to note that the accuracy of the EMA test is contingent upon the patient’s continued consumption of gluten; if gluten is eliminated from the diet, the antibody response may not be present, leading to potentially misleading results. Additionally, the EMA test may be less sensitive in individuals with mild celiac disease or in children under the age of 2 years, and it is often used in conjunction with other immunoassays to confirm the diagnosis of celiac disease.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The endomysial antibody (EMA) test is indicated for the following conditions:

  • Celiac Disease Diagnosis - The EMA test is primarily performed to help diagnose celiac disease, which is characterized by an abnormal immune response to gluten.
  • Assessment of Symptoms - It is indicated for patients presenting with symptoms such as recurring abdominal pain, bloating, chronic diarrhea or constipation, weight loss, and iron deficiency anemia.
  • Monitoring IgA Deficiency - The test is useful for evaluating patients with suspected IgA deficiency, where IgG testing may be necessary.
  • Confirmatory Testing - The EMA test may be used as a confirmatory test in conjunction with other immunoassays for celiac disease.

2. Procedure

The procedure for conducting the endomysial antibody (EMA) test involves several key steps:

  • Step 1: Patient Preparation - The patient should be advised to continue consuming a diet that includes gluten prior to the test to ensure accurate results, as the presence of antibodies is dependent on gluten intake.
  • Step 2: Blood Sample Collection - A venous blood sample is obtained from the patient, typically from the arm, using standard phlebotomy techniques to ensure a sterile and safe collection process.
  • Step 3: Serum Separation - The collected blood sample is processed in the laboratory to separate the serum, which contains the antibodies to be tested.
  • Step 4: Testing Methodology - The serum is then analyzed using the indirect immunofluorescent antibody (IFA) technique, which allows for the detection of endomysial antibodies present in the serum.
  • Step 5: Result Interpretation - The test yields a qualitative result indicating the presence or absence of EMA. If antibodies are detected, it supports the diagnosis of celiac disease, while negative results may require further investigation.

3. Post-Procedure

After the endomysial antibody (EMA) test is performed, the patient may resume normal activities immediately, as there are no specific post-procedure care requirements. However, it is essential for the patient to continue their gluten-containing diet until the test is completed to ensure the accuracy of the results. The healthcare provider will discuss the test results with the patient, and if the EMA test is positive, further evaluation and management for celiac disease may be necessary. In cases of negative results, additional testing or monitoring may be recommended based on the patient's symptoms and clinical history.

Short Descr EMA EACH IG CLASS
Medium Descr ENDOMYSIAL ANTIBODY EACH IMMUNOGLOBULIN CLASS
Long Descr Endomysial antibody (EMA), each immunoglobulin (Ig) class
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 3
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.
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.
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
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
Date
Action
Notes
2022-01-01 Added Code added
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