According to the Medicare LDRP L26890 related to Mammographies, a V16.3 (family history of malignant neoplasm of breast) is used only for mother, sister, and daughter. I find it very strange that grandmother, aunt and father are not included. Do you have any information contrary to the Medicare guideline? The ICD-9 Guidelines don't specify the specific relationship. I haven't been successful in finding any other information.