G0248: Demonstration, prior to initiation of home inr monitoring, for patient with either mechanical heart valve(s), chronic atrial fibrillation, or venous thromboembolism who meets medicare coverage criteria, under the direction of a physician; includes: face-to-face demonstration of use and care of the inr monitor, obtaining at least one blood sample, provision of instructions for reporting home inr test results, and documentation of patient's ability to perform testing and report results