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Official Description

Complement; total hemolytic (CH50)

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86162 refers to a laboratory test known as the total hemolytic complement (CH50) test. This blood test is specifically designed to measure the activity of the total hemolytic complement system, which is a crucial part of the immune response. The complement system consists of a series of proteins that work together to enhance the ability of antibodies and phagocytic cells to clear pathogens from an organism. The CH50 test evaluates the overall function of this system by assessing how well it can lyse (break down) red blood cells in the presence of complement proteins. The common language description indicates that this code can be utilized for two specific types of tests: the complement activity enzyme immunoassay and the complement activity alternative pathway test. The enzyme immunoassay is a semiquantitative test that measures the activity of the complement system, helping to identify any abnormalities or deficiencies that may be linked to various infectious diseases or inflammatory conditions, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and vasculitis. Additionally, the alternative pathway test also evaluates the functional activity of the complement system, focusing on a different pathway within the complement cascade. Abnormal results from these tests may suggest either inherited or acquired defects in one or more components of the complement system, which can have significant implications for a patient's health. It is important to note that a blood sample for this test is obtained through a separately reportable venipuncture, ensuring that the sample is collected properly for accurate testing. The testing methodologies employed include semiquantitative enzyme-linked immunosorbent assay for the complement activity enzyme test and semiquantitative radial immunodiffusion for the alternative pathway test.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The total hemolytic complement (CH50) test, represented by CPT® Code 86162, is indicated for the evaluation of various conditions that may affect the immune system. The following are the specific indications for performing this test:

  • Systemic Lupus Erythematosus (SLE) - A chronic autoimmune disease that can lead to inflammation and damage in various body systems, necessitating assessment of complement activity.
  • Rheumatoid Arthritis (RA) - An autoimmune disorder characterized by chronic inflammation of the joints, where complement activity may be altered.
  • Vasculitis - A group of disorders that cause inflammation of blood vessels, which may involve complement system abnormalities.
  • Infectious Diseases - Conditions where the complement system plays a role in the immune response, and its functionality may be compromised.

2. Procedure

The procedure for conducting the total hemolytic complement (CH50) test involves several key steps, which are outlined below:

  • Step 1: Patient Preparation - Prior to the test, the patient may be instructed to avoid certain medications or supplements that could interfere with the results. It is essential to ensure that the patient is adequately informed about the procedure and its purpose.
  • Step 2: Venipuncture - A qualified healthcare professional performs a venipuncture to obtain a blood sample from the patient. This step is crucial as the quality of the sample directly impacts the accuracy of the test results. The blood is collected in a sterile tube, which is then labeled appropriately for identification.
  • Step 3: Serum Preparation - After collection, the blood sample is processed to separate the serum from the cellular components. This is typically done by centrifugation, which allows for the clear serum to be extracted for testing.
  • Step 4: Testing Methodology - The serum is subjected to the complement activity enzyme immunoassay or the alternative pathway test, depending on the specific clinical question. The enzyme immunoassay utilizes a semiquantitative approach to measure complement activity, while the alternative pathway test employs semiquantitative radial immunodiffusion to assess functional activity.
  • Step 5: Result Interpretation - Once the testing is complete, the results are analyzed and interpreted by a qualified laboratory professional. Abnormal results may indicate potential deficiencies or dysfunctions within the complement system, warranting further clinical investigation.

3. Post-Procedure

After the total hemolytic complement (CH50) test is completed, the patient may be advised on any necessary follow-up actions based on the results. If the results indicate abnormal complement activity, further diagnostic testing or clinical evaluations may be recommended to determine the underlying cause. Patients are typically informed that they can resume normal activities immediately following the venipuncture, although they should monitor the site for any signs of excessive bleeding or infection. It is also important for healthcare providers to communicate the results to the patient in a timely manner, discussing any implications for their health and potential next steps in management or treatment.

Short Descr COMPLEMENT TOTAL (CH50)
Medium Descr COMPLEMENT TOTAL HEMOLYTIC
Long Descr Complement; total hemolytic (CH50)
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 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.
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.
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.
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.
GA Waiver of liability statement issued as required by payer policy, individual case
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
Date
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2011-01-01 Changed Short description changed.
Pre-1990 Added Code added.
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