Billing and Coding: MolDX: Testing of Multiple Genes

A panel of genes is a distinct procedural service from a series of individual
genes. All services billed to Medicare must be reasonable and necessary. As
such, if a provider or supplier submits a claim for a panel, then the
patient's medical record must reflect that the panel was reasonable and
necessary. Alternatively, if a provider or supplier bills for a number of
individual genes, then the patient's medical record must reflect that each
individual gene is reasonable and necessary.

Refer to [Billing and Coding: MolDX: Molecular Diagnostic Tests (MDT)
A57527](https://www.cms.gov/medicare-coverage-
database/view/article.aspx?articleid=57527&ver=25&bc=0) CPT/HCPCS Codes that
are applicable to this article.

For ease of reading the term "gene" when used in this document will be used to
indicate a gene, region of a gene, and / or variant(s) of a gene.

Genes can be assayed serially or in parallel. Genes assayed on the same date
of service are considered to be assayed in parallel if the result of 1 assay
does not affect the decision to complete the assay on another gene, and the 2
genes are being tested for the same indication. Genes assayed on the same date
of service are considered to be assayed serially when there is a reflexive
decision component where the results of the analysis of 1 or more genes
determines whether the results of additional analyses are reasonable and
necessary.

If a laboratory assays 2 or more genes in a patient in parallel, then those 2
or more genes will be considered part of the same panel. A panel constitutes a
single procedural service, so 1 HCPCS codes must be submitted for the panel.
If the laboratory assays genes in serial, then the laboratory must submit
claims for genes individually. The order by the treating clinician must
reflect whether the treating clinician is ordering a panel or single genes,
and additionally, the patient's medical record must reflect that the service
billed was reasonable and necessary.

**Two examples:**

**Single Service Example:** A clinician orders 5 specific genes associated
with breast cancer. The laboratory analyzes the 5 genes for common mutations
using polymerase chain reaction. All 5 PCR procedures are started prior to the
results of any 1 PCR procedure being known. The results are signed off on
simultaneously, and all 5 results are sent to a clinician.

This would be considered a single procedural service, a single 5 gene panel,
and it must be billed as such. This single panel must be reasonable and
necessary to be billed to Medicare.

**Multiple Distinct Procedural Services Example:** A clinician requests that
genes associated with early onset colorectal cancer be analyzed in a patient.
The clinician orders stepwise reflex testing where a negative or positive
result in 1 gene determines whether additional analysis on other genes will be
performed or what that will be.

Each gene assayed represents 1 procedural service, so if more than 1 gene is
analyzed, then multiple procedural services may be billed in some patients for
whom reflex testing goes beyond the first gene. Each gene billed to Medicare
must be individually reasonable and necessary. A clinician's order is not by
itself sufficient to indicate that a test was reasonable and necessary. The
record must reflect that the test is used in the management of the
beneficiary's specific medical problem in accordance with CFR 410.32.

Labs must register a test with the Diagnostics Exchange as it reflected on the
order form and is run in the laboratory. If a gene / variant is tested as part
of a panel, then the lab must register the panel and must submit the correct
z-code and CPT code for the panel. If a lab has a panel but sometimes also
analyzes individual genes from the panel, the lab must register both the panel
and the individual genes that are analyzed.

In general 2 or more codes describing a genetic test billed on the same
beneficiary on the same date may constitute a panel, and if so the service
must be billed as a single procedural service. We would generally expect that
a provider or supplier would not bill for more than 2 distinct laboratory
genetic testing procedural services on a single beneficiary on a single date
of service. If providers or suppliers do bill for more than two distinct
laboratory genetic testing procedural services on a single beneficiary on a
single date of service, the provider or supplier must attest that each
additional service billed is a distinct procedural service using the 59
modifier.

The use of the 59 modifier will be considered an attestation that distinct
procedural services are being performed rather than a panel. Providers and
suppliers must use the 59 modifier in conjunction with other modifiers where
appropriate. When providers and suppliers bill for multiple distinct
procedural services, each service must be reasonable and necessary.

Laboratories that are billing for many individual genes using the 59 modifier
rather than panels may be subject to medical review as outliers.

When 2 or more codes are submitted for the same beneficiary on the same date
of service, the claims processing system will reject every code submitted
after the first service. However, if a lab runs more than 1 distinct
procedural service on a single date of service, then the lab must use the 59
modifier with each additional service billed as an attestation that it is a
distinct procedural service.