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Official Description

Insulin; total

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Insulin is a crucial hormone produced by the pancreas that plays a vital role in the regulation of blood glucose levels. It facilitates the utilization of circulating glucose for energy, while also promoting the storage of excess glucose as glycogen in liver and muscle cells. The measurement of total insulin levels in the blood is essential for assessing various metabolic conditions, particularly those related to diabetes and insulin resistance. The procedure involves obtaining a blood sample through a process known as venipuncture, which is separately reportable. The specimen can be collected at a random time, or it may be taken when the patient is fasting, or at specific timed intervals (30, 60, 90, or 120 minutes) following a 75-gram glucose challenge. The test for total insulin levels, identified by CPT® Code 83525, utilizes a quantitative chemiluminescent immunoassay to analyze serum or plasma samples. This method provides a precise measurement of the total insulin present in the bloodstream, which is critical for diagnosing and managing conditions related to insulin production and glucose metabolism.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

Testing for total insulin levels is indicated in various clinical scenarios, particularly for the evaluation of metabolic disorders. The following conditions may warrant this procedure:

  • Diabetes Mellitus Assessment of insulin production and regulation in patients diagnosed with diabetes.
  • Insulin Resistance Evaluation of insulin levels in patients suspected of having insulin resistance, which is often associated with conditions like obesity and metabolic syndrome.
  • Hypoglycemia Investigation of unexplained low blood sugar levels to determine if excessive insulin production is a contributing factor.
  • Monitoring Ongoing assessment of insulin levels in patients undergoing treatment for diabetes or other related conditions.

2. Procedure

The procedure for measuring total insulin levels involves several key steps, which are outlined below:

  • Step 1: Patient Preparation Prior to the blood draw, the patient may be instructed to fast for a specified period, depending on the clinical indication. In some cases, the blood sample may be taken at random or at timed intervals following a glucose challenge.
  • Step 2: Venipuncture A qualified healthcare professional performs venipuncture to obtain a blood sample. This involves inserting a needle into a vein, typically in the arm, to collect the necessary volume of blood into a collection tube.
  • Step 3: Sample Handling The collected blood sample is then processed to separate the serum or plasma, which is required for the insulin assay. Proper handling and storage of the specimen are crucial to ensure accurate test results.
  • Step 4: Laboratory Analysis The serum or plasma is subjected to a quantitative chemiluminescent immunoassay in the laboratory. This method allows for the precise measurement of total insulin levels in the sample.

3. Post-Procedure

After the blood sample has been collected, there are generally no specific post-procedure care requirements for the patient. However, patients may be advised to resume normal activities unless otherwise directed by their healthcare provider. The results of the total insulin test will be analyzed and reported, which may require further discussion with the healthcare provider to interpret the findings in the context of the patient's overall health and any existing medical conditions.

Short Descr ASSAY OF INSULIN
Medium Descr ASSAY OF INSULIN TOTAL
Long Descr Insulin; total
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 4
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.
GA Waiver of liability statement issued as required by payer policy, individual case
Q4 Service for ordering/referring physician qualifies as a service exemption
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
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.
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
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
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.
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.
GX Notice of liability issued, voluntary under payer policy
GZ Item or service expected to be denied as not reasonable and necessary
LT Left side (used to identify procedures performed on the left side of the body)
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
Action
Notes
2013-01-01 Changed Medium Descriptor changed.
Pre-1990 Added Code added.
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