2025 CPT code 83518
(Active) Effective Date: N/A Laboratory - Chemistry Procedures Pathology and Laboratory Feed
Immunoassay for analyte other than infectious agent antibody or infectious agent antigen, qualitative or semiquantitative, single step method (e.g., reagent strip).
Modifiers may be applicable to specify laterality (LT, RT), bilateral procedures (50), distinct procedural services (59), or other circumstances that impact the service provided. Refer to current modifier guidelines for appropriate usage.
Medical necessity for this code must be supported by the patient's clinical condition and the reason for ordering the test.The documentation should clearly indicate why the test is necessary for the diagnosis or treatment of the patient's condition.
Laboratory professionals perform the technical aspects of the test, including sample preparation, running the assay, and interpreting the results.The ordering physician is responsible for requesting the test and using the results in patient care.
In simple words: This test checks for a substance in a sample of your bodily fluid, like blood or urine. It's a simple, quick test that uses a special strip to give a yes/no or an approximate amount of the substance.
This code represents a single-step immunoassay test used to detect or semi-quantitatively measure an analyte that is not an infectious agent antibody or antigen. The method used is typically a single-step process like a reagent strip.
Example 1: A patient presents with symptoms suggestive of a thyroid condition. A rapid single-step immunoassay test for thyroid stimulating hormone (TSH) is performed using a reagent strip to get a preliminary assessment of thyroid function., A urine sample is tested for the presence of hCG (human chorionic gonadotropin) using a single-step immunoassay pregnancy test strip., A patient with joint pain undergoes arthrocentesis (joint aspiration). The synovial fluid is tested for alpha-defensin using a single-step immunoassay test strip as an aid in diagnosing periprosthetic joint infection.
Documentation should include the reason for the test, the type of specimen collected, the date and time of collection, the test result, and any relevant clinical findings.
** While many simple chemistry tests use this code due to the lack of specific analyte codes, always check for more specific CPT codes before using 83518. Note that tests performed using this code should not be considered CLIA-waived.
- Payment Status: Active
- Specialties:Various specialties may use this code depending on the analyte being tested. Examples include family medicine, internal medicine, endocrinology, obstetrics/gynecology, orthopedics, and rheumatology.
- Place of Service:This test can be performed in various settings, including physician offices, hospitals (inpatient or outpatient), independent laboratories, and other healthcare facilities.