CMS Home PT/INR Monitoring Coverage Policy Update: What Billing Teams Need to Know (NCD 269)
The Centers for Medicare & Medicaid Services (CMS) has issued a modification to National Coverage Determination (NCD) 269, governing home prothrombin time/international normalized ratio (PT/INR) monitoring for anticoagulation management. This update, effective March 12, 2026, affects billing and coverage determinations for Medicare patients who self-test with home INR monitors while on warfarin therapy. If your practice serves patients with mechanical heart valves, chronic atrial fibrillation, or venous thromboembolism, this policy directly affects how you document and bill for these services.
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Home Prothrombin Time/International Normalized Ratio (PT/INR) Monitoring for Anticoagulation Management |
| Policy Code | NCD 269 |
| Change Type | Modified |
| Effective Date | 2026-03-12 |
| Impact Level | Medium |
| Specialties Affected | Cardiology, Hematology, Internal Medicine, Primary Care, Anticoagulation Clinics |
| Key Action | Review patient eligibility and documentation requirements to confirm all four coverage criteria are met before billing for home PT/INR monitoring services. |
What CMS NCD 269 Covers: Home INR Monitoring for Medicare Patients
CMS covers home PT/INR monitoring as a diagnostic test for Medicare beneficiaries who are on chronic oral anticoagulation therapy with warfarin. The clinical rationale is straightforward: warfarin has a narrow therapeutic index—less than a 2-fold difference between the median lethal dose and the median effective dose—which is why the FDA has designated it a black-box drug requiring close monitoring since October 4, 2006.
The goal of home monitoring is to improve time in therapeutic range (TTR). Better TTR directly reduces thromboembolic events (stroke, pulmonary embolism, deep vein thrombosis) and hemorrhagic complications. For select patient populations, CMS has determined that patient self-testing and self-management using a home INR monitor is an appropriate and covered approach to achieving that goal.
The policy covers home PT/INR monitoring for services furnished on or after March 19, 2008, and this NCD 269 modification continues to carry that coverage forward under updated policy versioning (269-v2).
CMS Medicare Coverage Criteria: Four Requirements That Must All Be Met
This is where documentation discipline becomes critical. CMS will only cover home PT/INR monitoring when the treating physician prescribes both the monitor and the home testing, per 42 CFR 410.32(a), AND all four of the following requirements are satisfied:
| # | Covered Indication |
|---|---|
| 1 | Three-month anticoagulation history: The patient must have been on anticoagulation therapy for at least three months prior to beginning home INR device use. |
| 2 | Completed face-to-face education: The patient must have completed a formal, face-to-face educational program on anticoagulation management and must have demonstrated correct device use before testing at home. |
| 3 | Ongoing correct device use: The patient must continue to correctly use the device as part of their ongoing anticoagulation management after home monitoring begins. |
| 4 | Testing frequency limit: Self-testing must not occur more frequently than once per week. |
All four criteria must be met simultaneously. A gap in any one of them—especially documented device training or the three-month anticoagulation history—is a denial waiting to happen.
Which Diagnoses Qualify Under CMS NCD 269
CMS has defined three nationally covered indications for home PT/INR monitoring under this NCD. The patient must have one of the following diagnoses and be on warfarin:
- Mechanical heart valves
- Chronic atrial fibrillation
- Venous thromboembolism (VTE)—explicitly inclusive of deep venous thrombosis (DVT) and pulmonary embolism (PE)
Any other indication for home PT/INR monitoring is not nationally covered under this NCD. Those other indications remain subject to local Medicare contractor (MAC) discretion under the "Other" provisions of this policy. If your patient is on warfarin for an indication outside these three categories, you'll need to verify coverage with the applicable MAC before providing the device or billing for monitoring services.
What Is Not Covered Nationally Under NCD 269
CMS lists no nationally non-covered indications in the formal exclusion section of this policy. However, the practical non-coverage boundary is clear: any home PT/INR monitoring that falls outside the three covered diagnosis categories—mechanical heart valves, chronic atrial fibrillation, and VTE—does not have national Medicare coverage under this NCD.
Also important: NCD 269 is entirely separate from the PT clinical laboratory NCD at section 190.17 of the NCD Manual (Publication 100-03). That NCD governs lab-based PT testing. Do not conflate the two when building your billing workflows or responding to audits.
| 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 |
Affected Codes
The current NCD 269-v2 policy document does not list specific CPT or HCPCS codes. Billing teams should reference the applicable Medicare Claims Processing transmittals—Transmittal 1562 and Transmittal 1663—for coding guidance. Contact your MAC or consult your coding resources to confirm the correct codes for the home INR monitoring device and associated professional services under current code sets.
Related ICD-10 Diagnosis Codes to support medical necessity documentation:
| Code | Description |
|---|---|
| I48.0–I48.19 | Atrial fibrillation (chronic forms) |
| Z95.2 | Presence of prosthetic heart valve |
| I82.4–I82.9 | Venous thromboembolism — deep venous thrombosis |
| I26.01–I26.99 | Pulmonary embolism |
Note: These ICD-10 codes reflect the three covered diagnosis categories described in the NCD narrative. Confirm coding accuracy against your current code set and MAC guidance.
What Your Billing Team Should Do
| # | Action Item |
|---|---|
| 1 | Audit active home INR patients immediately. Pull a list of all Medicare patients currently billed for home PT/INR monitoring. Confirm that each patient's chart documents all four eligibility criteria—three-month anticoagulation history, completed face-to-face education with demonstrated device competency, ongoing correct use, and weekly-or-less testing frequency. |
| 2 | Confirm diagnosis alignment before the effective date. For each patient, verify that the documented diagnosis is one of the three nationally covered indications: mechanical heart valve, chronic atrial fibrillation, or VTE (DVT or PE). Patients on warfarin for other reasons need MAC-level coverage verification before you continue billing under this NCD. |
| 3 | Update your intake and onboarding documentation templates. The face-to-face education requirement is frequently underdocumented. Create or update a standardized form that captures the date of education, the clinician who conducted it, and a documented attestation that the patient demonstrated correct device use. This becomes your first line of defense in an audit. |
| 4 | Consult Transmittals 1562 and 1663 for code-level guidance. Since NCD 269-v2 does not enumerate specific billing codes, your coding team should cross-reference these claims processing transmittals and verify current HCPCS codes with your MAC. |
| 5 | Flag non-covered indications for MAC review. Build a workflow flag in your EHR or billing system to route any home PT/INR claims for diagnoses outside the three covered categories to a manual MAC coverage check before submission. |
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