G0250 HCPCS - PHYSICIAN REVIEW, INTERPRETATION, AND PATIENT MANAGEMENT OF HOME INR TESTING FOR PATIENT WITH EITHER MECHANICAL HEART VALVE(S), CHRONIC ATRIAL FIBRILLATION, OR VENOUS THROMBOEMBOLISM WHO MEETS MEDICARE COVERAGE CRITERIA; TESTING NOT OCCURRING MORE FREQUENTLY THAN ONCE A WEEK; BILLING UNITS OF SERVICE INCLUDE 4 TESTS