Need help choosing the right code?
Ask CasePilot about procedures, modifiers, bundling, and coding guidance.
Try CasePilot© Copyright 2026 American Medical Association. All rights reserved.
The CPT® Code 86361 refers to a laboratory test that measures the absolute count of CD4 T-cells in a blood sample. CD4 T-cells are a specific type of lymphocyte, which are white blood cells that play a crucial role in the immune system, particularly in cell-mediated immunity. This test is particularly significant in the context of HIV infection, as the HIV virus specifically targets and destroys CD4 cells, leading to a weakened immune system. The absolute CD4 count is essential for categorizing the stage of HIV infection according to the guidelines set forth by the Centers for Disease Control and Prevention (CDC). It serves as a critical tool for healthcare providers to determine when to initiate treatment in asymptomatic patients, adjust existing antiviral therapies, and monitor the effectiveness of treatment over time. For individuals diagnosed with HIV, it is recommended that the absolute CD4 count be assessed every 3 to 6 months to ensure proper management of the disease. The test is performed using quantitative flow cytometry, a sophisticated laboratory technique that allows for precise measurement of the CD4 T-cell population in the blood. According to CDC criteria, an individual with a CD4 count below 200 cells/mm³ is classified as having AIDS, which necessitates immediate medical intervention regardless of the presence of symptoms.
© Copyright 2026 Coding Ahead. All rights reserved.
The absolute CD4 count test is indicated for the following conditions:
The procedure for obtaining the absolute CD4 count involves several key steps:
After the procedure, patients may experience minor discomfort or bruising at the venipuncture site, which typically resolves quickly. There are no specific post-procedure care instructions required for the absolute CD4 count test. However, patients should be informed about the importance of follow-up appointments to discuss their results and any necessary changes to their treatment plan. Regular monitoring of the absolute CD4 count is recommended every 3 to 6 months for individuals with known HIV infection to ensure effective management of their condition.
| Short Descr | T CELL ABSOLUTE COUNT | Medium Descr | T CELLS ABSOLUTE CD4 COUNT | Long Descr | T cells; absolute CD4 count | 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 | GA | Waiver of liability statement issued as required by payer policy, individual case | GZ | Item or service expected to be denied as not reasonable and necessary | 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. | 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 | 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 | X5 | Diagnostic services requested by another clinician: for reporting services by a clinician who furnishes care to the patient only as requested by another clinician or subsequent and related services requested by another clinician; this modifier is reported for patient relationships that may not be adequately captured by the above alternative categories; reporting clinician service examples include but are not limited to, the radiologist's interpretation of an imaging study requested by another clinician | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
|
Date
|
Action
|
Notes
|
|---|---|---|
| 2011-01-01 | Changed | Short description changed. |
| 1998-01-01 | Added | First appearance in code book in 1998. |
Get instant expert-level medical coding assistance.