Noridian Administrative Services (NAS) is instructing providers how to bill for the lab test "Decision DX GMB" using CPT code 84999. In order to assist the treating physician in determining the patientâ€™s treatment plan, this test analyzes the genetics of a glioblastoma brain tumor.
To avoid the denial of "service not medically necessary", the following descriptive statement must be included in Item 19 of the CMS-1500 claim form or its electronic equivalent.
- "Decision DX GMB - results determine treatment plan"
In addition, documentation supporting this statement must be maintained in the patientâ€™s medical record.