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Official Description

Infectious agent drug susceptibility phenotype prediction using regularly updated genotypic bioinformatics

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 87900 refers to a laboratory test that predicts the drug susceptibility phenotype of infectious agents, specifically utilizing regularly updated genotypic bioinformatics. This test is particularly relevant in the context of viral infections, such as HIV, where understanding the drug resistance profile of the virus is crucial for effective treatment planning. The process involves phenotypic testing, which, while labor-intensive and technically challenging, is essential for measuring how susceptible a virus is to specific drugs. This is achieved by determining the concentration of a drug that can inhibit viral replication in vitro, providing valuable insights into the effectiveness of potential antiviral therapies. Genotypic bioinformatics plays a significant role in this predictive process by identifying viral mutations that are associated with known drug resistance, thereby enhancing the accuracy of susceptibility predictions. The test typically requires a blood sample, which is obtained through a separately reported venipuncture, and the serum or plasma is then analyzed using advanced techniques such as polymerase chain reaction (PCR) or sequencing. This test is particularly ordered for patients with new onset HIV infections to assess the drug resistance of the transmitted viral strain, aiding in the formulation of an appropriate treatment regimen. Additionally, it may be utilized for patients with established HIV infections who are experiencing suboptimal viral load suppression after starting treatment or who show signs of virologic failure, indicated by elevated plasma HIV RNA levels despite adequate dosing of their antiviral therapy.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The CPT® Code 87900 is indicated for use in specific clinical scenarios related to HIV infections. The following conditions warrant the performance of this test:

  • New Onset HIV Infection - The test is ordered to determine the drug resistance of the viral strain that has been transmitted to the patient, which is critical for planning an effective treatment regimen.
  • Established HIV Infection with Suboptimal Suppression - This test may be utilized for patients who have an established HIV infection and are experiencing inadequate suppression of their viral load following the initiation of a treatment regimen.
  • Virologic Failure - The test is also indicated for patients who demonstrate virologic failure, characterized by elevated plasma HIV RNA levels despite receiving adequate dosing of an antiviral therapy regimen.

2. Procedure

The procedure for CPT® Code 87900 involves several critical steps to ensure accurate prediction of drug susceptibility. The following procedural steps are outlined:

  • Step 1: Sample Collection - A blood sample is obtained from the patient through a venipuncture, which is reported separately. This step is essential as it provides the necessary biological material for testing.
  • Step 2: Serum/Plasma Preparation - Once the blood sample is collected, the serum or plasma is separated for analysis. This preparation is crucial as it isolates the components needed for the subsequent testing processes.
  • Step 3: Testing Using PCR/Sequencing - The prepared serum or plasma is subjected to polymerase chain reaction (PCR) or sequencing techniques. These advanced methodologies are employed to analyze the genetic material of the virus, allowing for the identification of mutations associated with drug resistance.
  • Step 4: Data Analysis and Interpretation - The results from the PCR or sequencing are interpreted using regularly updated genotypic bioinformatics. This analysis predicts the drug susceptibility phenotype of the infectious agent, providing critical information for treatment decisions.

3. Post-Procedure

After the procedure associated with CPT® Code 87900, the patient may not require any specific post-procedure care related to the blood draw itself, as it is a standard venipuncture. However, it is essential to monitor the patient for any potential adverse reactions to the blood draw, such as bruising or discomfort at the puncture site. The results of the test will be analyzed and reported, and healthcare providers will use this information to make informed decisions regarding the patient's treatment regimen. Follow-up appointments may be necessary to discuss the results and adjust the treatment plan based on the drug susceptibility predictions obtained from the test.

Short Descr PHENOTYPE INFECT AGENT DRUG
Medium Descr NFCT AGT DRUG SUSCEPT PHENOTYPE PREDICTION
Long Descr Infectious agent drug susceptibility phenotype prediction using regularly updated genotypic bioinformatics
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)
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.
GW Service not related to the hospice patient's terminal condition
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.
Date
Action
Notes
2011-01-01 Changed Short description changed.
2006-01-01 Added First appearance in code book in 2006.
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