Currentpriority healthPolicy N/A

HOME PROTHROMBIN TIME OR INR MONITORING

This policy governs coverage and medical necessity criteria for FDA‑approved home PT/INR monitoring devices and related services for members on chronic warfarin therapy, including training and frequency limits; it affects providers ordering, training, or billing for home INR testing.

Policy Summary

Payerpriority health

PolicyHOME PROTHROMBIN TIME OR INR MONITORING

Policy CodePolicy N/A

Change TypeAdded government/regulatory sectionsremoved Medicaid language

Effective DateSep 1, 2025

Next Review DateN/A

Key ActionEnsure patients complete a formal education program and have ≥3 months anticoagulation management before initiating FDA‑approved home INR monitoring.

SourceLink

POLICY UPDATE CHANGES

Removed Medicaid coverage language.

New sections: Government Regulations, and Guidelines/Position Statements.

3 monthsminimum prior anticoagulation management before home device use

once/weekmaximum recommended self-testing frequency

FDA approvedhome monitor requirement

NCD 190.11CMS NCD referenced

Coverage and Medical Necessity Criteria

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inv-01: Home PT/INR monitoring - medical necessity

Covered when ALL of the following are met:

Home INR monitoring coverage criteria: 1. The home monitor is FDA approved; 2. The patient has undergone anticoagulation management for at least 3 months prior to the use of the home INR device; 3. The patient must undergo a formal educational program on anticoagulation management and the use of the device prior to its use in the home; 4. Self-testing with the device is limited to a frequency of once per week. Testing more frequently than once per week is generally considered not medically necessary.see node texts

Follow CMS/NCD guidance where applicable.

inv-02: Not indicated agents

Agents for which PT/INR monitoring is not indicated: PT monitoring or INR is not medically necessary for agents that do not affect prothrombin time such as direct oral anticoagulants or low molecular weight heparin.N/A

DOACs are approved for use without PT monitoring.

PT monitoring or INR is not medically necessary for agents that do not affect prothrombin time, including direct oral anticoagulants (DOACs) and low molecular weight heparin. The policy specifies that PT/INR testing is intended for monitoring warfarin therapy and similar agents whose anticoagulant effect is reflected in the PT/INR; agents that do not alter prothrombin time do not require PT/INR monitoring and use of these tests for those agents is not indicated.

Self-testing with an FDA‑approved home INR device is limited to once per week. The policy states that testing more frequently than once per week is generally considered not medically necessary. Related CPT/HCPCS services (for example, G0249 and G0250) are defined with the same weekly testing limitation and note billing units based on up to 4 tests per month; services billed or provided at a frequency greater than weekly may be denied.

Testing Frequency Limits

Home PT/INR self-testing — Not more frequently than once per week for self-testing

Frequency limitSelf-testing with a home PT/INR device is limited to a frequency of once per week; testing more frequently than once per week is generally considered not medically necessary.

Device requirementHome monitor must be FDA approved.

Prior anticoagulation managementPatient must have undergone anticoagulation management for at least 3 months prior to use of the home INR device.

Education requirementPatient must complete a formal educational program on anticoagulation management and device use prior to home use.

Medicaid billing noteCertain related CPT/HCPCS services may not be covered for Priority Medicaid (see CPT/HCPCS list).

Coding — ICD-10, CPT and HCPCS

ICD-10 Codes that may applyICD-10

D68.52	Prothrombin gene mutation
D68.59	Other primary thrombophilia
D68.61	Antiphospholipid syndrome
D68.62	Lupus anticoagulant syndrome
I23.6	Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction
I26.01	Septic pulmonary embolism with acute cor pulmonale
I26.09	Other pulmonary embolism with acute cor pulmonale
I26.90	Septic pulmonary embolism without acute cor pulmonale
I26.99	Other pulmonary embolism without acute cor pulmonale
I27.82	Chronic pulmonary embolism

1–10 of 22

1/3

CPT/HCPCS CodesmixedCovered

93792	Patient/caregiver training for initiation of home international normalized ratio (INR) monitoring under the direction of a physician or other qualified health care professional, face-to-face, including use and care of the INR monitor, obtaining blood sample, instructions for reporting home INR test results, and documentation of patient's/caregiver's ability to perform testing and report results
93793	Anticoagulant management for a patient taking warfarin, must include review and interpretation of a new home, office, or lab international normalized ratio (INR) test result, patient instructions, dosage adjustment (as needed), and scheduling of additional test(s), when performed
G0248	Demonstration, prior to initial use, 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 ability to perform testing and report results
G0249	Provision of test materials and equipment for home INR monitoring of patient with either mechanical heart valve(s), chronic atrial fibrillation, or venous thromboembolism who meets Medicare coverage criteria; includes provision of materials for use in the home and reporting of test results to physician; not occurring more frequently than once a week; testing materials, billing units of service include 4 tests
G0250	Physician review, interpretation, and patient management of home INR testing for a 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.

Self-testing frequency — Not more frequently than once per week

Maximum frequencyNot more frequently than once per week for self-testing.

Medicare billing units (example)G0249 and G0250 specify testing not occurring more frequently than once a week; billing units include 4 tests.

Not medically necessary if exceededTesting more frequently than once per week is generally considered not medically necessary and may be denied.

Provider Responsibilities and Administrative Requirements

Prior Authorization

Prior Authorization Required

Prior Authorization Required: Prior authorization may be required for certain drugs, services, and procedures related to at‑home PT/INR monitoring. When prior authorization is required, providers must submit a request demonstrating that the drug, service, or procedure is medically necessary per Priority Health requirements. See the Priority Health Provider Manual for detailed submission instructions.

Providers must demonstrate medical necessity in the prior authorization request.
Refer to Priority Health Provider Manual for submission processes and forms.

Note

Plan Applicability — Check Member Benefits

Consult member-specific benefits and plan documents before authorizing services. Coverage for at-home PT/INR monitoring is subject to the member's specific benefits, and group- or plan-specific documents may supersede this policy. For self-funded (ASO), individual, Medicare, and Medicaid/Healthy Michigan Plan members, follow the applicable plan documents and CMS or state guidance when present.

If a plan document conflicts with this policy, the plan document governs.
Medicare determinations prevail where CMS guidance exists.
For Michigan Medicaid members, verify coverage against the Michigan Medicaid Fee Schedule and Provider Manual.

Documentation Required

Documentation Required for Coverage

Required documentation for coverage includes evidence the home INR monitor is FDA approved, documentation that the patient has had at least 3 months of anticoagulation management prior to use, and evidence the patient completed a formal anticoagulation education program (including training on device use) prior to home use. Billing documentation should support frequency limits and, when applicable, use appropriate CPT/HCPCS codes for training, provision of materials, and management.

Document FDA approval (device labeling or manufacturer information).
Document ≥3 months prior anticoagulation management in the medical record.
Document completion of a formal education/training program and competency demonstration prior to home use.
Track and document testing frequency (self-testing limited to once per week).
Include appropriate CPT/HCPCS codes (e.g., 93792, 93793, G0248, G0249, G0250) on claims as applicable.

Denial Risk

Denial Triggers and Non‑Coverage

Denial risks include testing more frequently than once per week, use of PT/INR monitoring for agents that do not affect prothrombin time (for example direct oral anticoagulants or low‑molecular‑weight heparin), or insufficient documentation of required criteria (FDA approval, prior anticoagulation duration, or completion of formal education). Services not covered for Priority Medicaid are identified in the coding section.

Testing frequency > once per week — generally not medically necessary and may be denied.
PT/INR monitoring for agents that do not affect PT (DOACs, LMWH) — not medically necessary.
Incomplete documentation of FDA approval, prior 3 months anticoagulation, or training — may result in denial.

Ordering and Training Requirements

Step Therapy

Ordering requirements: confirm device, prior management, education, and PA

Ordering providers must confirm the patient meets all coverage criteria before ordering: the home monitor is FDA approved, the patient has had at least 3 months of anticoagulation management, the patient completed a formal education program, and prior authorization rules are followed when required.

Verify FDA approval of the specific home PT/INR device.
Confirm documentation of ≥3 months prior anticoagulation management.
Ensure completion of a formal anticoagulation/device education program before home use.
Follow prior authorization procedures and check member plan documents for product-specific applicability.

Key Definitions

INR — definition and standardization details

DefinitionINR (International Normalized Ratio) is the ratio of a patient's prothrombin time compared to the mean PT for a group of normal individuals, standardized to allow comparison across labs and times.

PurposeUsed to determine degree of anticoagulation and guide dose adjustments of warfarin to optimize time in therapeutic range (TTR).

Measurement methodHome monitors measure capillary whole-blood prothrombin time (PT) to derive INR for patients on warfarin.

Self-testing vs self-management — definitions and differences

Self-testingPatient measures INR at home using a portable monitor and reports results to their clinician for interpretation and management.

Self-managementPatient measures INR at home and uses an individualized algorithm to adjust warfarin dosage themselves (patient-directed dose changes).

Clinical goalBoth approaches aim to improve time in therapeutic range (TTR) and reduce thromboembolic and bleeding events for select patients.

Background and Clinical Context

Warfarin anticoagulation requires periodic monitoring of PT/INR to determine the degree of anticoagulation and guide dose adjustments to optimize time in therapeutic range (TTR). Home INR monitors permit capillary whole‑blood measurement that patients can perform at home; results are either reported to clinicians for dosage adjustment or used with individualized algorithms for patient self‑management. For select patients, home self‑testing or self‑management can improve TTR and reduce thromboembolic and bleeding events. By contrast, direct oral anticoagulants (DOACs) and heparins do not require PT/INR monitoring and therefore are not indications for home INR testing.