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Official Description

Protein; electrophoretic fractionation and quantitation, serum

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 84165 refers to a laboratory test that measures the levels of proteins in serum through a process known as electrophoretic fractionation and quantitation. This test is essential for evaluating various health conditions by analyzing the protein composition in the blood. The procedure involves obtaining a blood sample, typically through venipuncture, which is a method of drawing blood from a vein. The serum, which is the liquid portion of the blood after clotting, is then subjected to electrophoresis. This technique separates proteins based on their size and charge, allowing for detailed analysis and quantification of different protein fractions. The results of this test can provide valuable insights into the presence of pathophysiologic states, including inflammation, gammopathies, and dysproteinemias. It is often performed alongside the total protein test (CPT® Code 84155) to give a comprehensive view of the protein levels and any abnormalities that may indicate underlying health issues. While this test is informative, it is important to note that there are more sensitive tests available for detecting similar disorders.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The protein electrophoretic fractionation and quantitation test (CPT® Code 84165) is indicated for the evaluation of various medical conditions. The following are the explicitly provided indications for performing this test:

  • Inflammation - This test helps in identifying the presence of inflammatory processes in the body, which can be indicative of various diseases.
  • Gammopathies - It is utilized to detect abnormal protein levels associated with gammopathies, which are disorders related to the immune system and the production of antibodies.
  • Dysproteinemias - The test is also indicated for diagnosing dysproteinemias, conditions characterized by abnormal protein levels in the blood, which can affect overall health.

2. Procedure

The procedure for performing the protein electrophoretic fractionation and quantitation test involves several key steps, which are detailed below:

  • Step 1: Sample Collection - A blood sample is obtained from the patient through a process known as venipuncture. This involves inserting a needle into a vein, typically in the arm, to draw blood into a collection tube. Proper technique is essential to ensure a sufficient sample is collected and to minimize discomfort for the patient.
  • Step 2: Serum Preparation - Once the blood sample is collected, it is allowed to clot, and then it is centrifuged to separate the serum from the cellular components of the blood. The serum is the clear liquid that remains after the blood has clotted and is crucial for the subsequent analysis.
  • Step 3: Electrophoretic Fractionation - The prepared serum is subjected to electrophoresis, a laboratory technique that uses an electric field to separate proteins based on their size and charge. This step allows for the identification of different protein fractions present in the serum.
  • Step 4: Quantitation - After separation, the individual protein fractions are quantified. This involves measuring the concentration of each protein type, which provides valuable information regarding the patient's health status and any potential abnormalities.

3. Post-Procedure

After the completion of the protein electrophoretic fractionation and quantitation test, the patient may experience minimal discomfort at the venipuncture site, which typically resolves quickly. There are no specific post-procedure care instructions required for this test. However, it is essential for healthcare providers to review the results in conjunction with the patient's clinical history and other diagnostic tests to make informed decisions regarding further evaluation or treatment. The results can help guide the management of conditions related to inflammation, gammopathies, and dysproteinemias.

Short Descr PROTEIN E-PHORESIS SERUM
Medium Descr PROTEIN ELECTROPHORETIC FRACTJ&QUANTJ SERUM
Long Descr Protein; electrophoretic fractionation and quantitation, serum
Status Code Active Code
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 6 - Laboratory Physician Interpretation Code
Multiple Procedures (51) 0 - No payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
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 233 - Laboratory - Chemistry and Hematology
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.
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.
GC This service has been performed in part by a resident under the direction of a teaching physician
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
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
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.
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
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.
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.
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
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
GW Service not related to the hospice patient's terminal condition
Q0 Investigational clinical service provided in a clinical research study that is in an approved clinical research study
XP Separate practitioner, a service that is distinct because it was performed by a different practitioner
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
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
56 Preoperative management only: when 1 physician or other qualified health care professional performed the preoperative care and evaluation and another performed the surgical procedure, the preoperative component may be identified by adding modifier 56 to the usual procedure number.
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.
AY Item or service furnished to an esrd patient that is not for the treatment of esrd
CR Catastrophe/disaster related
ER Items and services furnished by a provider-based, off-campus emergency department
GA Waiver of liability statement issued as required by payer policy, individual case
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
Q3 Live kidney donor surgery and related services
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)
SA Nurse practitioner rendering service in collaboration with a physician
X4 Episodic/focused services: for reporting services by clinicians who provide focused care on particular types of treatment limited to a defined period and circumstance; the patient has a problem, acute or chronic, that will be treated with surgery, radiation, or some other type of generally time-limited intervention; reporting clinician service examples include but are not limited to, the orthopedic surgeon performing a knee replacement and seeing the patient through the postoperative period
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.
2005-01-01 Changed Code description changed.
2004-01-01 Changed Code description changed.
Pre-1990 Added Code added.
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