Aetna modified CPB 0173 covering home INR testing devices, effective September 26, 2025. Here's what billing teams need to know before submitting claims under G0248, G0249, G0250, 93792, and 93793.
Aetna, a CVS Health company, updated its home prothrombin time (INR) testing coverage policy under CPB 0173 in the Aetna system. The policy governs durable medical equipment coverage for devices like the CoaguChek XS Plus, INRatio 2 PT/INR Monitoring System, and Coag-Sense Self-Test PT/INR Monitoring System for patients on chronic warfarin therapy. If your practice or DME supplier bills home INR monitoring for Aetna members, this policy update sets the exact criteria that determine whether a claim pays or denies.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Aetna, a CVS Health company |
| Policy | Prothrombin Time (INR) Home Testing Devices |
| Policy Code | CPB 0173 |
| Change Type | Modified |
| Effective Date | September 26, 2025 |
| Impact Level | Medium |
| Specialties Affected | Cardiology, Hematology, Internal Medicine, DME Suppliers, Anticoagulation Clinics |
| Key Action | Audit active home INR claims to confirm all three medical necessity criteria are documented before billing G0249 or 93793 |
Aetna Home INR Testing Coverage Criteria and Medical Necessity Requirements 2025
Aetna's Aetna home INR monitoring coverage policy is built on three hard gates. All three must be met before home INR testing qualifies as medically necessary. Miss one, and you're looking at a claim denial.
Here are the three criteria, exactly as stated in CPB 0173:
| # | Covered Indication |
|---|---|
| 1 | Duration: The expected need for home INR testing is six or more months. |
| 2 | Anticoagulation history: The patient must have been on anticoagulation therapy for at least three months before using the home device. |
| 3 | Frequency: Self-testing must not occur more than once per week. |
The qualifying diagnoses are specific. Aetna covers home INR testing for patients requiring chronic oral anticoagulation with warfarin for: mechanical heart valve, ventricular assist device, chronic atrial fibrillation, deep venous thrombosis, pulmonary embolism, venous embolism and thrombosis of deep vessels of the lower extremity, or hypercoagulable states. Hypercoagulable states include antithrombin III deficiency, Factor V Leiden, protein C deficiency, and protein S deficiency — map those to ICD-10 codes D68.51 through D68.62.
The policy does not explicitly list prior authorization requirements in the coverage criteria, but given Aetna's standard DME handling, your billing team should verify prior authorization requirements at the plan level before ordering devices. Reimbursement under G0249 for ongoing test materials and equipment depends on maintaining documented eligibility at every point of service.
The key codes here are G0248 (initial demonstration before first use), G0249 (provision of test materials and equipment for ongoing monitoring), and G0250 (physician review, interpretation, and patient management). On the professional side, CPT 93792 covers patient and caregiver training, and CPT 93793 covers anticoagulant management including review of home INR results.
Aetna Home INR Testing Exclusions and Non-Covered Indications
One exclusion is explicit and unambiguous in CPB 0173. Additional hardware and software systems used to download data from home INR testing units to computers — for anticoagulation management purposes — are not covered. Aetna classifies these as convenience items, not medically necessary equipment.
This matters practically. If your patient is using a connected monitoring platform that syncs INR data to a physician portal, the connectivity hardware is not separately billable under this policy. Don't bill it. A claim for that add-on equipment will deny, and it creates audit exposure.
No other experimental or investigational designations appear in the CPB 0173 policy summary for the core home INR testing devices themselves.
Coverage Indications at a Glance
| Indication | Coverage Status | Relevant Codes | Notes |
|---|---|---|---|
| Mechanical heart valve on chronic warfarin | Covered | G0248, G0249, G0250, 93792, 93793 | All three medical necessity criteria must be met |
| Ventricular assist device on chronic warfarin | Covered | G0248, G0249, G0250, 93792, 93793 | All three medical necessity criteria must be met |
| Chronic atrial fibrillation on chronic warfarin | Covered | G0248, G0249, G0250, 93792, 93793 | All three medical necessity criteria must be met |
| Deep venous thrombosis on chronic warfarin | Covered | G0248, G0249, G0250, 93792, 93793 | All three medical necessity criteria must be met |
| Pulmonary embolism on chronic warfarin | Covered | G0248, G0249, G0250, 93792, 93793 | All three medical necessity criteria must be met; use I26.x codes |
| Venous embolism / thrombosis of deep vessels of lower extremity | Covered | G0248, G0249, G0250, 93792, 93793 | All three medical necessity criteria must be met |
| Hypercoagulable states (antithrombin III deficiency, Factor V Leiden, protein C deficiency, protein S deficiency) | Covered | G0248, G0249, G0250; D68.51–D68.62 | All three medical necessity criteria must be met |
| Data download hardware/software for anticoagulation management | Not Covered | N/A | Classified as convenience items; will deny |
Aetna Home INR Monitoring Billing Guidelines and Action Items 2025
The effective date of September 26, 2025 means this policy is already live. If you haven't reviewed your active claims and orders against these criteria, do it now.
| # | Action Item |
|---|---|
| 1 | Audit your active home INR orders for the three-month anticoagulation history requirement. This is the criterion that catches people off guard. The patient must have been anticoagulated for at least three months before the home device is ordered. Confirm that your clinical documentation includes the start date of warfarin therapy, and that it predates the device order by at least 90 days. Missing this is a fast path to a claim denial. |
| 2 | Document the expected duration of need at the time of ordering. Aetna requires a six-month or greater expected need. Your order documentation and supporting clinical notes must state this explicitly. "Patient requires long-term anticoagulation" is not specific enough. Your physician notes should say the expected duration of home INR monitoring exceeds six months. |
| 3 | Cap testing frequency at once per week in your patient instructions and clinical records. Aetna won't cover testing that exceeds weekly frequency. If your clinical protocol calls for more frequent testing during dose adjustments, those tests won't be covered under home INR billing guidelines for this payer. Document that monitoring is expected to occur no more than once per week. |
| 4 | Stop billing for data download hardware and connectivity software. If your current charge capture includes any add-on equipment for syncing INR results to a provider system, remove it for Aetna patients. It's explicitly excluded under CPB 0173. Continuing to bill it after the September 26, 2025 effective date creates unnecessary denial volume and recoupment risk. |
| 5 | Confirm ICD-10 diagnosis code accuracy before billing. For hypercoagulable state diagnoses, use D68.51–D68.62 specifically. For pulmonary embolism, the policy supports a wide range of I26.x codes. Verify your coders are mapping to the specific subcategory codes, not unspecified codes, to avoid medical necessity mismatches on review. |
| 6 | Verify prior authorization requirements at the individual plan level. CPB 0173 is the coverage policy, but plan-level prior authorization requirements vary. Before billing G0249 for ongoing test supplies or submitting claims for 93793, check whether the specific Aetna plan requires prior auth for home INR durable medical equipment. If you're uncertain how this applies to your patient mix, talk to your compliance officer before billing. |
| 7 | Train your ordering physicians on the initial demonstration requirement. G0248 covers the initial demonstration of home INR monitoring prior to first use. This must happen before the first test, not after. Make sure your clinical workflow captures this service at the right point in the care sequence — billing it after the fact creates audit exposure. |
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
CPT, HCPCS, and ICD-10 Codes for Home INR Testing Under CPB 0173
Covered CPT Codes (When Selection Criteria Are Met)
| Code | Type | Description |
|---|---|---|
| 93792 | CPT | Patient/caregiver training for initiation of home international normalized ratio (INR) monitoring |
| 93793 | CPT | Anticoagulant management for a patient taking warfarin, must include review and interpretation of a home INR test result |
Covered HCPCS Codes (When Selection Criteria Are Met)
| Code | Type | Description |
|---|---|---|
| G0248 | HCPCS | Demonstration, prior to initial use, of home INR monitoring for patient with either mechanical heart valve or chronic atrial fibrillation |
| G0249 | HCPCS | Provision of test materials and equipment for home INR monitoring of patient with either mechanical heart valve or chronic atrial fibrillation |
| G0250 | HCPCS | Physician review, interpretation, and patient management of home INR testing for a patient with either mechanical heart valve or chronic atrial fibrillation |
Key ICD-10-CM Diagnosis Codes
| Code | Description |
|---|---|
| D68.51 | Activated protein C resistance — Thrombophilia |
| D68.52 | Prothrombin gene mutation — Thrombophilia |
| D68.53 | Antiphospholipid syndrome — Thrombophilia |
| D68.54 | Lupus anticoagulant syndrome — Thrombophilia |
| D68.55 | Thrombophilia due to hyperhomocysteinemia |
| D68.56 | Other thrombophilia — Thrombophilia |
| D68.57 | Antithrombin III deficiency — Thrombophilia |
| D68.58 | Other primary thrombophilia |
| D68.59 | Other thrombophilia |
| D68.60 | Protein C deficiency |
| D68.61 | Protein S deficiency |
| D68.62 | Other thrombophilia |
| H34.9 | Unspecified retinal vascular occlusion (arterial embolism to the eye) |
| I26.1 | Pulmonary embolism |
| I26.10 | Pulmonary embolism, unspecified |
| I26.11 | Saddle embolus of pulmonary artery with acute cor pulmonale |
| I26.12 | Saddle embolus of pulmonary artery without acute cor pulmonale |
| I26.13 | Single subsegmental pulmonary embolism without acute cor pulmonale |
| I26.14 | Multiple subsegmental pulmonary emboli without acute cor pulmonale |
| I26.15 | Pulmonary embolism with acute cor pulmonale |
| I26.16 | Pulmonary embolism with acute respiratory distress |
| I26.17 | Other pulmonary embolism with acute cor pulmonale |
| I26.18 | Pulmonary embolism — other |
| I26.19 | Pulmonary embolism — other |
| I26.2–I26.99 | Additional pulmonary embolism subcategories (see full code set in Aetna CPB 0173) |
The full ICD-10-CM code set under CPB 0173 includes 158 diagnosis codes spanning pulmonary embolism (I26.x), deep vein thrombosis, thrombophilia (D68.5x–D68.6x), and related vascular conditions. Review the complete list at the Aetna CPB 0173 source document before finalizing your ICD-10 mapping.
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