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 87184 refers to susceptibility studies that assess the effectiveness of antimicrobial agents against specific bacteria using the disk method. This procedure involves placing a bacterial isolate on an agar plate, where it is then exposed to disks impregnated with various antibiotic agents. The primary goal of this study is to determine which antibiotics are effective in inhibiting the growth of the bacteria in question. The disk method is a widely used laboratory technique that allows for the evaluation of up to 12 different antimicrobial agents simultaneously on a single plate. By observing the zones of inhibition around each disk, laboratory personnel can identify the susceptibility or resistance of the bacteria to the tested antibiotics. This information is crucial for guiding appropriate antibiotic therapy in clinical settings, ensuring that patients receive the most effective treatment for their infections.
© Copyright 2026 Coding Ahead. All rights reserved.
The susceptibility study using CPT® Code 87184 is indicated for the following conditions:
The procedure for conducting susceptibility studies using CPT® Code 87184 involves several key steps:
After the susceptibility study is completed, the results are analyzed and reported to the healthcare provider. The report will indicate which antibiotics were effective in inhibiting bacterial growth and which were not. This information is critical for guiding appropriate antibiotic therapy. Additionally, it is important to ensure that the results are communicated promptly to facilitate timely treatment decisions. Follow-up may be necessary to monitor the patient's response to the prescribed antibiotic therapy and to adjust treatment as needed based on clinical outcomes.
| Short Descr | MICROBE SUSCEPTIBLE DISK | Medium Descr | SUSCEPTIBILITY STUDY ANTIMICROBIAL DISK METHOD | Long Descr | Susceptibility studies, antimicrobial agent; disk method, per plate (12 or fewer agents) | 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 | 8 | 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. | 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. | GW | Service not related to the hospice patient's terminal condition | 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. | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | 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. | 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. | 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. | CC | Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed) | 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 | 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 | GZ | Item or service expected to be denied as not reasonable and necessary | RT | Right side (used to identify procedures performed on the right side of the body) | 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 | 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. |
| 2001-01-01 | Changed | Code description changed. |
| Pre-1990 | Added | Code added. |
Get instant expert-level medical coding assistance.