If a diagnosis code reflects the findings of a study, then the study was most likely a screening, and probably not medically necessary for the patient. For instance, with BMD testing, the patient must have a supporting diagnosis prior to the study according to HCFA's national policy. The policy does not allow for routine screening. No. 1747, June 1998 FL 67. 89-1260 or HCFA approved errata and supplements to this publication.
Hospitals report the diagnosis to their highest degree of certainty.
Diagnosis codes are not required on nonpatient claims for laboratory services where a hospital is functioning as an independent laboratory. Medicare requires that providers code for the diagnosis that most accurately reflects the reason for performing the service. That is, the ICD-9 diagnosis code should describe the symptoms or condition for which the patient has presented to a hospital or freestanding facility. This would lead to an over-counting of conditions. ICD-9 diagnosis codes should describe the symptoms and signs for the patient, corresponding to the reason the referring physician ordered the exam.