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Official Description

Infectious agent detection by nucleic acid (DNA or RNA); severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease [COVID-19]), amplified probe technique

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 87635 refers to the detection of infectious agents through nucleic acid amplification techniques, specifically targeting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for coronavirus disease (COVID-19). This procedure utilizes an amplified probe technique to identify the presence of the virus's genetic material, either DNA or RNA, in a sample. Nucleic acid amplification tests (NAATs) are highly sensitive and capable of detecting even minute quantities of viral genetic material, making them essential for accurate diagnosis. The process involves amplifying a specific segment of the viral RNA, which is first converted into DNA through a reverse transcription process, allowing for effective detection. Samples for testing can be collected from various respiratory sites, including the nose, throat, bronchus, or lungs, using methods such as swabbing or bronchoalveolar lavage. The procedure is critical in confirming the presence of SARS-CoV-2, especially in symptomatic individuals or during outbreaks, and plays a vital role in public health efforts to control the spread of COVID-19.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The CPT® Code 87635 is indicated for the detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients suspected of having coronavirus disease (COVID-19). This test is particularly relevant in the following scenarios:

  • Symptomatic Patients Patients exhibiting symptoms consistent with COVID-19, such as fever, cough, and difficulty breathing, may require testing to confirm the presence of the virus.
  • Asymptomatic Individuals Individuals who have been exposed to confirmed cases of COVID-19 or are part of screening protocols may also be tested to identify potential carriers of the virus.
  • Public Health Surveillance Testing is essential for monitoring and controlling outbreaks within communities, ensuring timely identification of cases to implement necessary public health measures.

2. Procedure

The procedure for CPT® Code 87635 involves several critical steps to ensure accurate detection of SARS-CoV-2. The following outlines the detailed procedural steps:

  • Sample Collection A sample is collected from the patient, typically from the respiratory tract, using methods such as nasopharyngeal swabbing, throat swabbing, or bronchoalveolar lavage. This step is crucial as it provides the biological material needed for testing.
  • Sample Preparation The collected sample undergoes processing to remove fats and proteins. This is achieved through the application of various chemical solutions that help isolate the RNA present in the sample, including both the patient's own RNA and that of the virus, if it is present.
  • Reverse Transcription Since SARS-CoV-2 contains RNA, the next step involves converting this RNA into DNA through a reverse transcription process. An enzyme is added to facilitate this conversion, allowing for the subsequent amplification of the viral genetic material.
  • Amplification Setup Oligonucleotide probes and primers, which are tagged with fluorescent dyes, are introduced to the sample. These probes specifically bind to the target nucleic acid sequence, marking it for amplification.
  • Amplification Process The prepared sample is placed in a real-time reverse transcription-polymerase chain reaction (RT-PCR) machine. The sample is cycled through a series of chemical reactions that double the amount of target DNA with each cycle, effectively amplifying the viral genetic material.
  • Fluorescence Measurement As the amplification occurs, the fluorescent markers attached to the newly created DNA copies emit signals that are measured by the RT-PCR machine in real time. The level of fluorescence indicates the presence of the virus.
  • Result Interpretation When the fluorescence reaches a predetermined threshold, it confirms the presence of SARS-CoV-2 in the sample. The number of cycles required to reach this level can also provide insights into the viral load, which may assist in assessing the severity of the infection.

3. Post-Procedure

After the completion of the testing procedure associated with CPT® Code 87635, the results are typically available within a few hours to a couple of days, depending on the laboratory's capabilities. It is essential for healthcare providers to communicate the results to the patient promptly, especially if a positive result is obtained, as this may necessitate immediate isolation and further clinical management. Additionally, healthcare professionals should consider follow-up testing or monitoring based on the patient's clinical status and public health guidelines. Proper documentation of the test results and any subsequent actions taken is crucial for compliance and continuity of care.

Short Descr SARS-COV-2 COVID-19 AMP PRB
Medium Descr IADNA SARS-COV-2 COVID-19 AMPLIFIED PROBE TQ
Long Descr Infectious agent detection by nucleic acid (DNA or RNA); severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease [COVID-19]), 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) Yes
APC Status Indicator Service Paid under Fee Schedule or Payment System other than OPPS
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) none
MUE 2
QW Clia waived test
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.
CR Catastrophe/disaster related
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.
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.
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
GC This service has been performed in part by a resident under the direction of a teaching physician
CS Cost-sharing waived for specified covid-19 testing-related services that result in and order for or administration of a covid-19 test and/or used for cost-sharing waived preventive services furnished via telehealth in rural health clinics and federally qualified health centers during the covid-19 public health emergency
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
GZ Item or service expected to be denied as not reasonable and necessary
SA Nurse practitioner rendering service in collaboration with a physician
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
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
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
32 Mandated services: services related to mandated consultation and/or related services (eg, third party payer, governmental, legislative or regulatory requirement) may be identified by adding modifier 32 to the basic procedure.
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.
92 Alternative laboratory platform testing: when laboratory testing is being performed using a kit or transportable instrument that wholly or in part consists of a single use, disposable analytical chamber, the service may be identified by adding modifier 92 to the usual laboratory procedure code (hiv testing 86701-86703, and 87389). the test does not require permanent dedicated space, hence by its design may be hand carried or transported to the vicinity of the patient for immediate testing at that site, although location of the testing is not in itself determinative of the use of this modifier.
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.
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
AW Item furnished in conjunction with a surgical dressing
CA Procedure payable only in the inpatient setting when performed emergently on an outpatient who expires prior to admission
ER Items and services furnished by a provider-based, off-campus emergency department
FP Service provided as part of family planning program
GE This service has been performed by a resident without the presence of a teaching physician under the primary care exception
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
KX Requirements specified in the medical policy have been met
LT Left side (used to identify procedures performed on the left side of the body)
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
PO Excepted service provided at an off-campus, outpatient, provider-based department of a hospital
Q5 Service furnished under a reciprocal billing 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
QJ Services/items provided to a prisoner or patient in state or local custody, however the state or local government, as applicable, meets the requirements in 42 cfr 411.4 (b)
TC Technical component; under certain circumstances, a charge may be made for the technical component alone; under those circumstances the technical component charge is identified by adding modifier 'tc' to the usual procedure number; technical component charges are institutional charges and not billed separately by physicians; however, portable x-ray suppliers only bill for technical component and should utilize modifier tc; the charge data from portable x-ray suppliers will then be used to build customary and prevailing profiles
U6 Medicaid level of care 6, as defined by each state
U7 Medicaid level of care 7, as defined by each state
UB Medicaid level of care 11, as defined by each state
UD Medicaid level of care 13, as defined by each state
X1 Continuous/broad services: for reporting services by clinicians, who provide the principal care for a patient, with no planned endpoint of the relationship; services in this category represent comprehensive care, dealing with the entire scope of patient problems, either directly or in a care coordination role; reporting clinician service examples include, but are not limited to: primary care, and clinicians providing comprehensive care to patients in addition to specialty care
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
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
Date
Action
Notes
2022-01-01 Note Grammar correction
2022-01-01 Changed Code description changed.
2021-01-01 Added First appearance of code in codebook.
2020-03-13 Added Code added.
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