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Official Description

Infectious agent detection by nucleic acid (DNA or RNA); Staphylococcus aureus, methicillin resistant, amplified probe technique

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 87641 refers to the detection of the infectious agent Staphylococcus aureus, specifically the methicillin-resistant strain (MRSA), through a nucleic acid amplification technique. This method utilizes either DNA or RNA to identify the presence of the pathogen in a sample. The amplified probe technique is a sophisticated diagnostic tool that serves as an alternative to traditional culturing methods, which can be time-consuming and may not always detect low levels of the infectious agent. By employing nucleic acid detection, healthcare professionals can identify infections more rapidly and accurately. The process involves extracting the nucleic acid from the infectious agent's cells and using a specific probe to hybridize with the target DNA or RNA. This probe is designed to bind to the complementary strands of the pathogen's genetic material, allowing for the formation of stable double-stranded complexes. The amplified probe technique enhances sensitivity, enabling the detection of even minimal quantities of the infectious agent, sometimes down to a single organism. This is achieved through methods such as polymerase chain reaction (PCR), which enzymatically replicates specific sequences of the target DNA, thereby amplifying it exponentially. The use of amplification primers, which are short strands of DNA that are complementary to the target DNA, further facilitates this process by ensuring that the polymerase enzyme can effectively copy the desired region, resulting in a significant increase in the amount of detectable genetic material.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The CPT® Code 87641 is indicated for the detection of methicillin-resistant Staphylococcus aureus (MRSA) infections. This procedure is particularly useful in clinical scenarios where rapid identification of MRSA is critical for effective patient management and treatment. The following conditions may warrant the use of this diagnostic test:

  • Suspected MRSA Infection Patients presenting with signs and symptoms indicative of a Staphylococcus aureus infection, particularly when there is a high suspicion of methicillin resistance.
  • Wound Infections Infections in surgical or traumatic wounds where MRSA is a potential pathogen.
  • Pneumonia Cases of pneumonia where MRSA is suspected, especially in patients with a history of prior MRSA infections or those with risk factors for resistant infections.
  • Skin and Soft Tissue Infections Patients with skin and soft tissue infections that are not responding to standard antibiotic therapy, prompting the need for MRSA identification.
  • Sepsis In cases of sepsis where the source of infection is unclear, and MRSA is a potential causative agent.

2. Procedure

The procedure for CPT® Code 87641 involves several critical steps to ensure accurate detection of methicillin-resistant Staphylococcus aureus. The following outlines the procedural steps:

  • Sample Collection A specimen is collected from the patient, which may include swabs from infected sites, blood, or other bodily fluids suspected of containing the infectious agent.
  • Nucleic Acid Extraction The collected sample undergoes a process to extract nucleic acids (DNA or RNA) from the Staphylococcus aureus cells. This step is crucial for isolating the genetic material necessary for detection.
  • Probe Hybridization A laboratory-prepared probe, which consists of complementary nucleic acid strands, is introduced to the extracted nucleic acids. The probe binds specifically to the target sequences of the MRSA DNA or RNA, forming stable complexes.
  • Amplification The amplified probe technique is employed, utilizing polymerase chain reaction (PCR) or similar methods to exponentially replicate the target DNA sequences. This amplification process increases the sensitivity of the test, allowing for the detection of even low levels of the infectious agent.
  • Detection The final step involves analyzing the amplified nucleic acids, often using fluorescence or other detection methods to confirm the presence of methicillin-resistant Staphylococcus aureus in the sample.

3. Post-Procedure

After the procedure associated with CPT® Code 87641, the results are typically available within a short timeframe, allowing for prompt clinical decision-making. It is essential for healthcare providers to interpret the results in conjunction with clinical findings and other diagnostic tests. Patients may require follow-up care based on the results, including adjustments to antibiotic therapy if MRSA is detected. Additionally, infection control measures may be implemented to prevent the spread of MRSA, particularly in healthcare settings. Proper documentation of the procedure and results is crucial for compliance and billing purposes.

Short Descr MR-STAPH DNA AMP PROBE
Medium Descr IADNA S AUREUS METHICILLIN RESIST AMP PROBE TQ
Long Descr Infectious agent detection by nucleic acid (DNA or RNA); Staphylococcus aureus, methicillin resistant, amplified probe technique
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)
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.
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
GW Service not related to the hospice patient's terminal condition
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
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.
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GA Waiver of liability statement issued as required by payer policy, individual case
RT Right side (used to identify procedures performed on the right side of the body)
LT Left side (used to identify procedures performed on the left side of the body)
Q4 Service for ordering/referring physician qualifies as a service exemption
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
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.
95 Synchronous telemedicine service rendered via a real-time interactive audio and video telecommunications system: synchronous telemedicine service is defined as a real-time interaction between a physician or other qualified health care professional and a patient who is located at a distant site from the physician or other qualified health care professional. the totality of the communication of information exchanged between the physician or other qualified health care professional and the patient during the course of the synchronous telemedicine service must be of an amount and nature that would be sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction. modifier 95 may only be appended to the services listed in appendix p. appendix p is the list of cpt codes for services that are typically performed face-to-face, but may be rendered via a real-time (synchronous) interactive audio and video telecommunications system.
99 Multiple modifiers: under certain circumstances 2 or more modifiers may be necessary to completely delineate a service. in such situations modifier 99 should be added to the basic procedure, and other applicable modifiers may be listed as part of the description of the service.
GC This service has been performed in part by a resident under the direction of a teaching physician
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
PD Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
SA Nurse practitioner rendering service in collaboration with a physician
T5 Right foot, great toe
TA Left foot, great toe
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
Date
Action
Notes
2011-01-01 Changed Short description changed.
2007-01-01 Added First appearance in code book in 2007.
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