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Official Description

Pretreatment of serum for use in RBC antibody identification; by differential red cell absorption using patient RBCs or RBCs of known phenotype, each absorption

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86978 refers to the process of pretreating serum for the purpose of identifying red blood cell (RBC) antibodies. This procedure involves the differential red cell absorption technique, which utilizes either the patient's own red blood cells or red blood cells of a known phenotype. The goal of this pretreatment is to enhance the identification of antibodies present in the serum, which can be crucial for various medical evaluations, including blood transfusions and compatibility testing. In this context, the serum, which is derived from the patient's blood sample, is treated with specific antigens by adding red blood cells that have these antigens already attached. This interaction allows for a more accurate identification of any antibodies that may be present in the serum. It is important to note that if the serum sample is diluted prior to the addition of red blood cells, the appropriate code to use would be 86976. Alternatively, if an inhibitor is introduced to neutralize a drug that may be affecting the serum, the correct code would be 86977. The specific code 86978 is designated for instances where the red blood cells and serum are incubated together before proceeding with the testing, ensuring that the antibodies can be effectively identified.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The procedure associated with CPT® Code 86978 is indicated for the identification of red blood cell antibodies in patients. This is particularly important in scenarios such as:

  • Blood Transfusion Compatibility Ensuring that the blood type of a donor matches that of the recipient to prevent transfusion reactions.
  • Hemolytic Disease of the Newborn Assessing the risk of hemolytic disease in newborns due to maternal antibodies that may attack the infant's red blood cells.
  • Autoimmune Hemolytic Anemia Diagnosing conditions where the immune system mistakenly attacks the body's own red blood cells.

2. Procedure

The procedure for CPT® Code 86978 involves several key steps to ensure accurate identification of RBC antibodies. These steps include:

  • Step 1: Collection of Serum A blood sample is collected from the patient, and the serum is separated from the red blood cells through centrifugation. This serum contains antibodies that need to be tested.
  • Step 2: Preparation of Red Blood Cells Red blood cells with known phenotypes or the patient's own red blood cells are prepared for the absorption process. These cells are selected based on the specific antigens that need to be tested against the serum.
  • Step 3: Incubation The prepared red blood cells are then incubated with the serum. This incubation allows for the interaction between the antibodies in the serum and the antigens on the red blood cells, facilitating the identification of any antibodies present.
  • Step 4: Testing After incubation, the mixture is tested to identify the presence of antibodies. This may involve additional laboratory techniques to confirm the results.

3. Post-Procedure

Post-procedure care for patients undergoing the RBC antibody identification process typically involves monitoring for any adverse reactions, especially if the procedure is part of a larger blood transfusion protocol. The results of the antibody identification will be documented and communicated to the healthcare provider for further action, which may include additional testing or treatment based on the findings. It is essential to ensure that the patient is informed about the results and any necessary follow-up actions that may be required.

Short Descr RBC PRETREATMENT SERUM
Medium Descr PRETX SERUM RBC ANTIBODY ID DIFFIAL EACH ABSRPJ
Long Descr Pretreatment of serum for use in RBC antibody identification; by differential red cell absorption using patient RBCs or RBCs of known phenotype, each absorption
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 STV-Packaged Codes
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) T1H - Lab tests - other (non-Medicare fee schedule)
MUE 1
CCS Clinical Classification 235 - Other Laboratory
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.
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.
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.
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
Date
Action
Notes
2011-01-01 Changed Short description changed.
1993-01-01 Added First appearance in code book in 1993.
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