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 83519 refers to a specific type of immunoassay that is utilized for the quantitative measurement of an analyte, which is a chemical substance other than an infectious agent antibody or antigen. This procedure is particularly significant in the realm of laboratory diagnostics, as it allows for the detection and quantification of various substances that may be indicative of non-infectious diseases and disorders. The term 'quantitative' indicates that the test provides a precise measurement of the analyte's concentration in the sample, rather than merely indicating its presence or absence. The radioimmunoassay (RIA) method, which is the focus of this code, employs radioisotope-labeled antigens or other substances that bind to the specific analyte being tested. This binding process enables the accurate quantification of minute quantities of various substances, including enzymes and hormones, which are critical for diagnosing conditions such as myasthenia gravis, pancreatic disease, and parathyroid disease, among others. In practice, the use of CPT® Code 83519 is essential for reporting quantitative RIA tests, which are distinguished from other quantitative testing methods, such as those reported under CPT® Code 83520. The RIA technique is particularly valuable in clinical settings where precise measurements of specific analytes are necessary for effective patient management and treatment planning.
© Copyright 2026 Coding Ahead. All rights reserved.
The CPT® Code 83519 is indicated for use in various clinical scenarios where the measurement of specific non-infectious analytes is necessary. These indications may include, but are not limited to, the following conditions:
The procedure associated with CPT® Code 83519 involves several key steps that ensure accurate measurement of the analyte in question. These steps are as follows:
Post-procedure care following the use of CPT® Code 83519 typically involves the interpretation of the test results by a qualified healthcare professional. The results provide critical information regarding the levels of the specific analyte tested, which can influence diagnosis and treatment decisions. Patients may be monitored for any symptoms related to the conditions being assessed, and follow-up testing may be scheduled as necessary to track changes in analyte levels over time. Additionally, proper documentation of the test results and any subsequent clinical actions taken is essential for maintaining accurate medical records and ensuring continuity of care.
| Short Descr | RIA NONANTIBODY | Medium Descr | IMMUNOASSAY ANALYTE QUANT RADIOIMMUNOASSAY | Long Descr | Immunoassay for analyte other than infectious agent antibody or infectious agent antigen; quantitative, by radioimmunoassay (eg, RIA) | 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 | 5 | CCS Clinical Classification | 233 - Laboratory - Chemistry and Hematology |
| 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. | 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. | 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 | Q4 | Service for ordering/referring physician qualifies as a service exemption | 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. | GZ | Item or service expected to be denied as not reasonable and necessary | GA | Waiver of liability statement issued as required by payer policy, individual case | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service | 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. | 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. | AY | Item or service furnished to an esrd patient that is not for the treatment of esrd | G8 | Monitored anesthesia care (mac) for deep complex, complicated, or markedly invasive surgical procedure | 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 | 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
|
|---|---|---|
| 2010-01-01 | Changed | Code description changed. |
| 1993-01-01 | Added | First appearance in code book in 1993. |
Get instant expert-level medical coding assistance.