Quick coding chart: Definitive drug test — G0659

Why This Topic Matters

Definitive drug testing is frequently audited and denied when documentation, coverage, or payer policy does not align with the reported lab service. This article helps readers identify the relevant code set and understand the surrounding reimbursement and medical-necessity context.

Article Sections

1. Overview

   Introduces the lab code and explains the general payment and utilization context surrounding definitive drug testing in physician practices.

2. Code G0659

   Presents the main code entry and a plain-language summary of the service category covered by the article.

3. Medicare payment information for G0659 — 2017

   Summarizes payment status and lab fee schedule information associated with the code for the referenced year.

4. Sample ICD-10-CM codes that may support medical necessity

   Lists example diagnosis codes referenced as potential supporting diagnoses for the service.

5. Coder’s notes

   Provides general billing and policy considerations related to reporting frequency, coverage review, documentation, and payer differences.