Home Prothrombin Time International Normalized Ratio (INR) Monitoring

Date of Revision: 7/5/02 

Description

Warfarin is the oral anticoagulant most frequently used to control and prevent thromboembolic disorders.  The goal of anticoagulant therapy is to administer the lowest possible dose of anticoagulant to prevent clot formation or expansion.  The required degree of anticoagulation continues to evolve as studies provide more information about the efficacy and safety of lower doses.  

The prothrombin time (PT) is the primary assay used in monitoring warfarin therapy.  The standardized use of the International Normalized Ratio (INR) allows physicians to determine the level of anticoagulation in a patient independent of the laboratory reagents used.  The INR is the ratio of the patient’s population time compared to the mean prothrombin time for a group of normal individuals.  The current therapeutic INR goal for patients with mechanical prosthetic heart valves is 2.5-3.5. 

The monitoring of patient’s INR level to maintain patients within the therapeutic range is accomplished in a physician’s office, anticoagulant clinics, or home monitoring.  Patient self-testing and self-management through the use of a home INR monitor may be used to improve the time in therapeutic rate for a select group of patients.  This policy addresses coverage of home monitoring of INR levels. 

Indications and Limitations of Coverage and/or Medical Necessity 

Effective for services performed on or after July 1, 2002, carriers will cover the use of home prothrombin time INR monitoring for anticoagulation management for patients with mechanical heart valves on warfarin.  The monitor and the home testing must be prescribed by a physician and the following patient requirements must be met: 

• Must have been anticoagulated for at least three months prior to use of the home INR device;
• Must undergo an educational program on anticoagulation management and the use of the device prior to its use in the home; and
• Self testing with the device is limited to a frequency of once per week.

NOTE:  Porcine valves are not covered so Medicare will not make payment on home INR monitoring for patients with porcine valves. 

CPT/HCPCS Codes

ICD-9 Codes that Support Medical Necessity 

Reasons for Denials 

When performed for indications other than those listed in the "Indications and Limitations of Coverage and/or Medical Necessity" section of this policy. 

Noncovered ICD-9 Codes 

Any diagnosis codes not listed in the "ICD-9 Codes That Support Medical Necessity" section of this policy. 

Coding Guidelines

The cost of the device and supplies are included in the payment for G0249, therefore, are not separately billable to the carriers. 

Documentation Requirements

Medical record documentation maintained in the patient’s file must support that the coverage requirements are met.  In addition, the documentation must support that the procedure was performed.  This information is normally found in the office/progress notes, hospital records, and test results. 

Utilization Guidelines 

HCPCS code G0250 is per 4 tests, therefore, this code should only be billed no more than once every 4 weeks.