Coding Ahead
CasePilot
Medical Coding Assistant
Case2Code
Search and Code Lookup Tool
CareerCenter
Medical Coding Job Board
Log in Register free account

Need help choosing the right code?

Ask CasePilot about procedures, modifiers, bundling, and coding guidance.

Try CasePilot

Official Description

Counterimmunoelectrophoresis, each antigen

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Counterimmunoelectrophoresis (CIEP) is a specialized laboratory technique utilized to identify and measure the presence of specific antigens and antibodies in a sample. This method operates by applying an electrical charge to a diffusion medium, which causes oppositely charged antigens and antibodies to migrate toward each other. The result is a rapid and sensitive detection of very low concentrations of these substances, making it particularly useful in clinical diagnostics. CIEP has been effectively employed to assess various antigens, including those associated with infectious diseases such as hepatitis (HAA), influenza, pneumococcus, rabies, Group B coxsackie virus, and cytomegalovirus (CMV). When performing this procedure, it is essential to report CPT® Code 86185 for each antigen that is tested, ensuring accurate coding and billing for the laboratory services rendered.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The counterimmunoelectrophoresis (CIEP) procedure is indicated for the detection and measurement of specific antigens and antibodies in various clinical scenarios. This technique is particularly useful in the following situations:

  • Hepatitis (HAA) Detection of hepatitis antigens to aid in the diagnosis of hepatitis infections.
  • Influenza Identification of influenza virus antigens for timely diagnosis and treatment.
  • Pneumococcus Measurement of pneumococcal antigens to assist in diagnosing pneumococcal infections.
  • Rabies Testing for rabies virus antigens in suspected cases of rabies exposure.
  • Group B Coxsackie Virus Detection of Group B coxsackie virus antigens in patients presenting with related symptoms.
  • Cytomegalovirus (CMV) Identification of CMV antigens to support the diagnosis of CMV infections.

2. Procedure

The counterimmunoelectrophoresis procedure involves several key steps to ensure accurate detection of antigens. Each step is critical to the overall success of the test:

  • Step 1: Sample Preparation The first step involves the collection and preparation of the biological sample, which may include serum or other bodily fluids. The sample is then treated to ensure that it is suitable for the CIEP process, which may involve dilution or other preparatory techniques.
  • Step 2: Application of Electrical Charge Once the sample is prepared, an electrical charge is applied to the diffusion medium. This charge facilitates the movement of the oppositely charged antigens and antibodies toward each other, allowing for their interaction and binding.
  • Step 3: Observation and Measurement After the migration of the antigens and antibodies has occurred, the results are observed and measured. This may involve visual inspection or the use of specialized equipment to quantify the binding and migration patterns, which indicate the presence of specific antigens.

3. Post-Procedure

Following the counterimmunoelectrophoresis procedure, it is important to analyze the results accurately. The laboratory will interpret the findings based on the binding patterns observed during the test. Clinicians may need to follow up with additional testing or clinical evaluations based on the results obtained. There are typically no specific post-procedure care requirements for patients, as the procedure is performed in a laboratory setting and does not involve invasive techniques. However, timely communication of results to the healthcare provider is essential for appropriate patient management and treatment decisions.

Short Descr COUNTERIMMUNOELECTROPHORESIS
Medium Descr CNTERIMMUNOELECTROPHORESIS EACH ANTIGEN
Long Descr Counterimmunoelectrophoresis, each antigen
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
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 Not applicable/unspecified.
CCS Clinical Classification 235 - Other Laboratory
Date
Action
Notes
2017-12-31 Deleted Code deleted.
Pre-1990 Added Code added.
CasePilot

Get instant expert-level medical coding assistance.

Ask about:
CPT Codes Guidelines Modifiers Crosswalks NCCI Edits Compliance Medicare Coverage
Example: "What is CPT code 99213?" or "Guidelines for E/M services"