This Medicare contractor herein identifies general limitations to coverage of
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)-based testing of
germline genetic material of the Medicare beneficiary.

This contractor does not consider any laboratory test that investigates the
same germline genetic content, for the same genetic information, that has
already been tested in the same Medicare beneficiary to be reasonable and
necessary as it is duplicative.

Germline testing, including using gene panels that contain some genetic
content that has already been tested in the same Medicare beneficiary may be
considered reasonable and necessary provided that there is established
clinical utility present in the remaining, non-duplicative genetic components
of the test. Unit of Service (UOS) for any one specific germline DNA or RNA-
based test is limited to one per lifetime. Examples of germline tests include
(but are not limited to) single gene and gene panel tests for: hereditary
cancer syndromes or cancer predisposition, inherited disorders, and
pharmacogenomics/cytochrome P450 testing.

Providers should take reasonable measures to be aware of what if any germline
testing a beneficiary has had prior to billing for germline testing so as to
avoid billing Medicare for services that are not reasonable and necessary.
Clinicians who order germline testing may wish to be aware of whether the test
that they are ordering is covered under Medicare and may wish to verify that
they are not ordering repeat germline testing.

**Background**

Patient DNA and RNA testing typically identify alterations or variants of
nucleotides in the genetic code, which can range from pathogenic mutations to
benign polymorphisms. These alterations can take the form of single nucleotide
variants, insertions and/or deletions, splice-site variants, copy number
alterations of genes or chromosomes, and inversions or translocations, among
others.1 They can be found in coding regions or non-coding regions. Germline
testing is differentiated from somatic testing in that somatic testing
identifies alterations specific to an individual cell or group of cells
derived from that cell (such as a neoplasm or clonal hematopoietic cells)
whereas germline testing seeks to identify inherited variants or alleles that
are present in all the patient's cells and make up a baseline genetic code of
the individual.2 Although somatic alterations are constantly occurring during
the life of an individual, the germline sequence of an individual does not
change over time.

Clinical utility of germline testing in Medicare beneficiaries has previously
been established for several conditions.3-7 However, as repeated testing of
the same genetic information does not by its nature provide new clinical
information, this contractor does not believe it is either reasonable or
necessary to perform such services more than once.

_Level of Evidence_

_Quality of evidence  - Strong_

_Strength of evidence - Strong_

_Weight of evidence  - Strong_

By definition, germline alleles/variants do not change. Some allowance must be
made for incidental repeat testing or for specific situations where
technological changes require revisiting the same genomic regions with
different approaches or targets. For more details, please review the
associated Billing and Coding Article.