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Official Description

Human leukocyte antigen (HLA) crossmatch, non-cytotoxic (eg, using flow cytometry); first serum sample or dilution

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Human leukocyte antigens (HLA) are specific protein molecules located on the surface of most body cells, playing a crucial role in the immune system's ability to recognize foreign cells. These antigens are vital for determining compatibility in organ and tissue transplant procedures. In the context of transplantation, the presence of specific HLA markers is assessed to ensure that the donor and recipient are compatible. This assessment process, known as HLA typing, is conducted separately before the crossmatch procedure. Ideally, a successful transplant occurs when the donor and recipient share identical HLA markers. However, if there are discrepancies in HLA types, the transplant may still proceed if the recipient has not developed antibodies against the donor's HLA markers. The presence of such antibodies can lead to an immune response that attacks the transplanted cells, tissue, or organ. To perform the HLA crossmatch, blood samples are collected from both the donor and recipient. The donor's cells are then combined with the recipient's serum, and the reaction is monitored using a non-cytotoxic method, such as flow cytometry. A negative reaction signifies that the recipient lacks antibodies against the donor's HLA, allowing the transplant to proceed, while a positive reaction indicates the presence of antibodies, which would prevent the transplant from being performed. For the initial serum sample or dilution, the appropriate code to use is 86825, while subsequent samples or dilutions are coded with 86826.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The HLA crossmatch procedure is indicated in the following scenarios:

  • Transplant Compatibility Assessment This procedure is performed to evaluate the compatibility between a donor and a recipient prior to organ or tissue transplantation.
  • Antibody Detection It is used to determine if the recipient has developed antibodies against the donor's HLA markers, which could lead to transplant rejection.

2. Procedure

The HLA crossmatch procedure involves several critical steps to ensure accurate compatibility assessment:

  • Step 1: Blood Sample Collection Blood samples are obtained from both the donor and the recipient. This is a crucial first step, as the samples will be used to identify the presence of HLA markers and any antibodies that may exist.
  • Step 2: HLA Typing Prior to the crossmatch, HLA typing is performed to identify the specific HLA markers present in both the donor and recipient. This step is essential for understanding the compatibility between the two parties.
  • Step 3: Mixing Samples The donor's cells are mixed with the recipient's serum in a controlled laboratory environment. This mixture allows for the observation of any immunological reactions that may occur.
  • Step 4: Reaction Observation The mixture is then observed for evidence of a reaction using a non-cytotoxic methodology, such as flow cytometry. This step is critical for determining whether the recipient has antibodies against the donor's HLA markers.
  • Step 5: Interpretation of Results A negative reaction indicates that the recipient does not have antibodies against the donor's HLA, suggesting compatibility for transplantation. Conversely, a positive reaction indicates the presence of antibodies, which would contraindicate the transplant.

3. Post-Procedure

After the HLA crossmatch procedure, the results are analyzed and documented. If the crossmatch is negative, the transplant team may proceed with the transplantation process, as the recipient is deemed compatible with the donor. If the crossmatch is positive, further evaluation and potential alternative strategies may be considered to address the incompatibility. It is essential for the healthcare team to communicate the results to both the donor and recipient, ensuring that all parties are informed of the implications for the transplant procedure.

Short Descr HLA X-MATH NON-CYTOTOXIC
Medium Descr HLA CROSSMATCH NONCYTOTOXIC 1ST SERUM/DILUTION
Long Descr Human leukocyte antigen (HLA) crossmatch, non-cytotoxic (eg, using flow cytometry); first serum sample or dilution
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 206 - Microscopic examination (bacterial smear, culture, toxicology)

This is a primary code that can be used with these additional add-on codes.

86826 Addon Code MPFS Status: Statutory exclusion (from MPFS, may be paid under other methodologies) APC Q4 Human leukocyte antigen (HLA) crossmatch, non-cytotoxic (eg, using flow cytometry); each additional serum sample or sample dilution (List separately in addition to primary procedure)
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.
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.
GZ Item or service expected to be denied as not reasonable and necessary
Date
Action
Notes
2011-01-01 Changed Short description changed.
2010-01-01 Added -
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