CPT: 83525

Expected Turnaround Time

24 Hours

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements




SST (Serum), Red Top (Separate Serum)

Storage Instructions

Room Temp., Refrigerated (2-8 C)

Stability Requirements

Room temp. 72hrs., Refrigerated 7 days

Test Details

Additional Information

An insulin test is a blood test used to measure the insulin levels being produced in the body. It is primarily used in one of the following ways: 

  • Diagnose an insulinoma, verify that removal of the tumor has been successful, and/or monitor for recurrence 
  • Diagnose the cause of hypoglycemia in an individual 
  • Identify insulin resistance 
  • Monitor the amount of insulin produced by the beta cells in the pancreas (endogenous); in this case, a C-peptide test may also be done. 
  • Determine when a type 2 diabetic might need to start taking insulin to supplement oral medications 
  • Determine and monitor the success of an islet cell transplant intended to restore the ability to make insulin by measuring the insulin-producing capacity of the transplant 

Testing for insulin may be ordered with glucose and C-peptide tests. Insulin levels are also sometimes used with the glucose tolerance test (GTT). In this situation, blood glucose and insulin levels are measured at pre-established intervals to evaluate insulin resistance. 

This test measures the amount of insulin in the blood – a hormone produced and stored in the beta cells of the pancreas. It is secreted in response to elevated blood glucose following a meal and is vital for transporting and storing glucose, the body’s main energy source. Carrying glucose from the blood to cells, insulin helps regulate blood glucose levels and has a role in lipid metabolism. 

Insulin and glucose blood levels must be in balance. After a meal, carbohydrates usually are broken down into glucose and other simple sugars. These are absorbed into the blood, causing the blood glucose level to rise and stimulating the pancreas to release insulin into the blood. As glucose moves into cells, the level in the blood decreases, and the release of insulin by the pancreas decreases. 

If a person cannot produce enough insulin, or if the body’s cells resist its effects (insulin resistance), glucose cannot reach most of the cells, and they starve. Meanwhile, blood glucose rises to an unhealthy level. This can cause disturbances in normal metabolic processes, resulting in various disorders and complications, including kidney disease, cardiovascular disease, and vision and neurological problems. 


  1. Donner T, Muñoz M. Update on insulin therapy for type 2 diabetes. J Clin Endocrinol Metab. 2012 May;97(5):1405-13. [PMC free article] [PubMed] 
  2. Howard-Thompson A, Khan M, Jones M, George CM. Type 2 Diabetes Mellitus: Outpatient Insulin Management. Am Fam Physician. 2018 Jan 01;97(1):29-37. [PubMed] 

Statement on Medical Necessity
All ordered tests should be medically necessary for the diagnosis or detection of disease, illness, impairment, symptom, syndrome, or disorder and the results should be used in the medical management and treatment decisions for the patient. Solaris requires ICD-10 codes with each order for lab testing and both the tests ordered and the diagnosis should be documented in the provider’s medical record for the patient. The United States Department of Health and Human Services, Office of Inspector General, takes the position that a provider who orders medically unnecessary tests may be subject to civil penalties.

Panels and Profiles
Solaris offers Providers the convenience of ordering test combinations in a group at times with the flexibility to choose appropriate test(s) for individual patients. Providers should only order those tests that he or she believes are medically necessary for each patient, and a lesser inclusive profile or individual tests should be ordered if not all tests in the test combination/profile are medically necessary. All tests offered in a test combination/profile may be ordered separately as individual tests. Solaris encourages clients to contact their Solaris representative if the testing configurations shown do not meet individual needs for any reason, or if some other combination of procedures is needed.

CPT Codes
CPT Codes listed are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are the responsibility of the billing party and are listed here for informational purposes. Correct coding may vary from one carrier to another. Solaris may bill specific carriers using codes other than what is shown.


For questions or inquiries related to testing please reach out to or contact us by phone at (844) 550-0308.