**Abstract:**  
  
Flow cytometry is a rapid and convenient technique for generating
immunophenotypic data. A flow cytometer measures multiple properties of cells
suspended in a moving fluid medium. As each particle passes single-file
through a laser light source, it produces a characteristic light pattern that
is measured by multiple detectors for scattered light (forward and 90 degrees)
and fluorescent light (if the cell is stained with a fluorochrome). Statement
of coverage - This LCD describes CGS indications and limitations of coverage.  
  
 **Indications:**  
  
The diagnosis and classification of hematopoietic neoplasms, including
assessment of biologic parameters associated with prognosis, detection of
antigens used as therapeutic targets and detection of residual neoplastic
cells following therapy.  
  
It is also useful to monitor lymphocyte populations in patients with HIV
infection; to monitor lymphocyte subpopulations in post transplant patients on
immunosuppressive therapy; to identify disease specific cell antigens when
complementing other diagnostic methods which may fail to yield a diagnosis
[e.g., CD59 in paroxysmal nocturnal hemoglobinuria (PNH)]; and to determine
CD34 count for stem cell transplant purposes.  
  
 **Other Comments:**  
  
For claims submitted to the Part A MAC: This coverage determination also
applies within states outside the primary geographic jurisdiction with
facilities that have nominated CGS Administrators, LLC to process their
claims.  
  
Bill type codes only apply to providers who bill these services to the Part A
MAC. Bill type codes do not apply to physicians, other professionals and
suppliers who bill these services to the carrier or Part B MAC.  
  
A pathologist may perform additional tests under the following circumstances:

  * These services are medically necessary so that a complete and accurate diagnosis can be reported to the treating physician/practitioner;
  * The results of the tests are communicated to and are used by the treating physician/practitioner in the treatment of the beneficiary; and
  * The pathologist documents in his/her report why additional testing was done.
  *   
  
Limitation of liability and refund requirements apply when denials are likely,
whether based on medical necessity or other coverage reasons. The
provider/supplier must notify the beneficiary in writing, prior to rendering
the service, if the provider/supplier is aware that the test, item or
procedure may not be covered by Medicare. The limitation of liability and
refund requirements do not apply when the test, item or procedure is
statutorily excluded, has no Medicare benefit category, or is rendered for
screening purposes.  
  
For dates of service on or after April 1, 2010, bill type 77X should be used
to report FQHC services.  
  
For outpatient settings other than CORFs, references to "physicians"
throughout this policy include non-physicians, such as nurse practitioners,
clinical nurse specialists, and physician assistants. Such non-physician
practitioners, with certain exceptions, may certify, order and establish the
plan of care for Flow Cytometry services as authorized by State law. (See
Sections 1861[s][2] and 1862[a][14] of Title XVIII of the Social Security Act;
42 CFR, Sections 410.74, 410.75, 410.76, and 419.22; 58 FR 18543, April 7,
2000.)