Throughout the United States, reimbursement for new laboratory technology is not well understood by the clinicians and laboratory personnel who provide it. It is important to understand how new technology will be paid for in today's changing, more tightly controlled, health-care funding environment. For flow cytometry testing, specifically, this confusion is not just restricted to providers of the tests. The carriers from many states still list flow cytometry as "investigational", contrary to the 1988 HCFA ruling. Although the HCFA ruling is not subject to interpretation by state Medicare carriers, it is often up to the provider whose claims are being denied to educate the carrier concerning its mistake. When confronted with the appropriate evidence (sometimes including a phone call from the regional HCFA office), most carriers relent. It is critical to note that claims must be billed correctly. This means that approved ICD-9-CM codes must be used with the appropriate CPT-4 codes. If there is no prevailing rate established in the state or if it has been established prohibitively low, it will be necessary to lobby and educate the carrier in regard to the medical necessity of the testing, as well as justifying the cost. This can be done by providing the medical director of the carrier with all necessary patient information, laboratory reports, and scientific literature validating the use of the technology for each individual claim. It may also require submitting cost justification data supporting the request. The importance of the development of a good working relationship with one's local Medicare carrier cannot be overemphasized. This relationship is a critical component of establishing a fair and appropriate rate for the reimbursement of any test.