CMS modified NCD 169 governing home oxygen coverage, effective March 7, 2026. Here's what billing teams need to do.
The Centers for Medicare & Medicaid Services updated its home use of oxygen coverage policy under NCD 169 in the Medicare system. This modification affects durable medical equipment suppliers, pulmonary practices, home health agencies, and any provider billing for home oxygen therapy. The policy does not list specific HCPCS codes in this version update, but the medical necessity criteria that drive your oxygen billing — and your claim denial risk — are precisely defined here.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Centers for Medicare & Medicaid Services (CMS) |
| Policy | Home Use of Oxygen — NCD 169 |
| Policy Code | NCD 169 Medicare |
| Change Type | Modified |
| Effective Date | March 7, 2026 |
| Impact Level | High |
| Specialties Affected | Pulmonology, Home Health, DME Suppliers, Internal Medicine, Sleep Medicine |
| Key Action | Audit your qualifying test documentation against the updated Group I and Group II criteria before billing home oxygen claims after March 7, 2026 |
CMS Home Oxygen Coverage Criteria and Medical Necessity Requirements 2026
The CMS home oxygen coverage policy under NCD 169 is built around one clinical concept: documented hypoxemia. No hypoxemia documentation, no coverage. That's the whole policy in one sentence.
Home oxygen billing stands or falls on the qualifying test. CMS requires a clinical test ordered and evaluated by the treating practitioner. The standard test is an arterial blood gas measuring the partial pressure of oxygen (PO2). Ear or pulse oximetry is also acceptable, but only when ordered and evaluated by the treating practitioner and performed under their supervision — or performed by a qualified provider or supplier of laboratory services.
Here's where billing teams get burned: a DME supplier is explicitly not a qualified provider or supplier of laboratory services under this NCD. If your oxygen supplier is conducting or ordering the qualifying test, that test does not satisfy the requirement. This prohibition does not extend to blood gas tests conducted by a hospital certified to perform them.
When both arterial blood gas and oximetry studies exist and the results conflict, the arterial blood gas study is the preferred source for documenting medical need. Train your documentation team to note this in the record — and make sure your claim documentation uses the correct study when both are in the chart.
Timing the Qualifying Test
The qualifying test must be performed "at the time of need." CMS defines this carefully, and it matters for reimbursement.
For inpatient hospital patients, the qualifying test must be performed within two days of discharge. Miss that window and you lose the qualifying test's validity for the home oxygen claim. For patients whose oxygen prescription originates outside a hospital stay, the test must be performed during the period when the treating practitioner notes signs and symptoms of illness that can be relieved by oxygen at home.
This is not a flexible standard. If the test was done weeks before the patient's acute need, it won't satisfy the requirement. Home oxygen billing that relies on stale qualifying studies is a claim denial waiting to happen.
Group I Coverage Criteria
Group I covers the most straightforward hypoxemia cases. A patient qualifies under any one of these three situations:
Rest: Arterial PO2 at or below 55 mm Hg, or arterial oxygen saturation at or below 88%, taken at rest while breathing room air.
Sleep: Arterial PO2 at or below 55 mm Hg, or arterial oxygen saturation at or below 88%, taken during sleep — for a patient who shows PO2 at or above 56 mm Hg or saturation at or above 89% while awake. Also covered under sleep criteria: a greater than normal fall in oxygen level during sleep, specifically a decrease in arterial PO2 of more than 10 mm Hg or a decrease in arterial oxygen saturation of more than 5%, associated with symptoms or signs attributable to hypoxemia (cognitive impairment, nocturnal restlessness, insomnia). For sleep-only coverage, CMS covers only one type of oxygen unit. Portable oxygen is not covered in this situation.
Exercise: Arterial PO2 at or below 55 mm Hg or arterial oxygen saturation at or below 88%, taken during exercise — for a patient who shows PO2 at or above 56 mm Hg or saturation at or above 89% at rest during the day. Exercise is defined as either the functional performance of the patient or a formal exercise test. In this case, supplemental oxygen is covered during exercise only if oxygen use improves the hypoxemia demonstrated during exercise on room air.
The exercise and sleep criteria carry specific equipment coverage limits. Your billing team needs to document which qualifying scenario applies — because that drives what equipment you can bill.
Group II Coverage Criteria
Group II is where the policy gets more complex, and where the published summary was truncated. The available language indicates Group II coverage is available for patients whose arterial PO2 and other clinical indicators fall into a secondary threshold range. If you treat patients who don't clearly meet Group I criteria, review the full NCD 169 text directly at the CMS source. Do not bill Group II claims based on incomplete documentation of the qualifying criteria.
If your team handles a mix of Group I and Group II patients and you're unsure how the updated criteria apply to your patient population, talk to your compliance officer before submitting claims under the March 7, 2026 effective date.
CMS Home Oxygen Exclusions and Non-Covered Indications
The NCD explicitly identifies one provider type as excluded from qualifying test authority: DME suppliers. A DME supplier cannot conduct or order the qualifying arterial blood gas or oximetry study and have that test satisfy the medical necessity documentation requirement.
Sleep-only qualifying patients face a specific equipment limitation. If the patient qualifies solely based on sleep-period hypoxemia, portable oxygen is not covered. Only one type of oxygen unit is covered in that scenario. Billing portable oxygen for a patient whose qualifying test was sleep-based is a direct path to claim denial.
Exercise-only qualifying patients face a parallel limit. Supplemental oxygen is covered during exercise only if it demonstrably improves the hypoxemia shown during the exercise test on room air. If the treating practitioner hasn't documented that oxygen improved the hypoxemia during exercise, the coverage basis doesn't hold.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Hypoxemia at rest — PO2 ≤55 mm Hg or O2 sat ≤88% breathing room air | Covered | Policy does not list specific codes | Qualifying test required; ordered and evaluated by treating practitioner |
| Hypoxemia during sleep — PO2 ≤55 mm Hg or sat ≤88% during sleep with normal waking values | Covered (sleep use only) | Policy does not list specific codes | Only one oxygen unit type covered; portable oxygen not covered |
| Sleep-related O2 drop — PO2 decrease >10 mm Hg or sat decrease >5% with associated symptoms | Covered (sleep use only) | Policy does not list specific codes | Symptoms must be attributable to hypoxemia; portable oxygen not covered |
| Hypoxemia during exercise — PO2 ≤55 mm Hg or sat ≤88% during exercise with normal resting values | Covered (exercise use only) | Policy does not list specific codes | Oxygen must demonstrably improve exercise-induced hypoxemia on room air |
| Group II hypoxemia criteria | Coverage status not fully determinable from available source data — review full NCD 169 text | Policy does not list specific codes | Source data was truncated at Group II section; access full NCD 169 text at CMS before billing |
| Qualifying test conducted by DME supplier | Not Covered | N/A | DME suppliers are explicitly excluded as qualified laboratory service providers |
| Portable oxygen — sleep-only qualifying patients | Not Covered | Policy does not list specific codes | Coverage restricted to one unit type for sleep indication only |
| Qualifying test performed outside "time of need" window | Not Covered | N/A | Inpatient: within 2 days of discharge; outpatient: during active illness period |
CMS Home Oxygen Billing Guidelines and Action Items 2026
| # | Action Item |
|---|---|
| 1 | Audit your qualifying test documentation now — before March 7, 2026. Pull a sample of your active home oxygen claims and confirm each one has a qualifying arterial blood gas or oximetry study ordered and evaluated by the treating practitioner. Any claim missing that documentation is a liability. |
| 2 | Verify the timing of every qualifying test against the "time of need" standard. For hospital discharges, the test must fall within two days of discharge. For community-based prescriptions, the test must align with the period when the treating practitioner documented signs and symptoms. Flag any claims where the test date doesn't clearly fit. |
| 3 | Document which qualifying group — rest, sleep, or exercise — applies to each patient. This drives equipment coverage. A patient who qualifies only during sleep cannot receive portable oxygen under this coverage policy. A patient who qualifies only during exercise receives supplemental oxygen for exercise use only. Your billing team needs this distinction documented before submission. |
| 4 | Remove DME supplier-conducted tests from your qualifying documentation workflows. If your oxygen supplier has been ordering or conducting the qualifying oximetry or blood gas study, that process does not satisfy the NCD 169 requirement. The test must come from a treating practitioner or a qualified laboratory — not the DME supplier. |
| 5 | When arterial blood gas and oximetry results conflict, bill from the arterial blood gas. That's CMS's stated preference under this policy. Make sure your claim documentation reflects the arterial blood gas study when both tests exist in the patient record. |
| 6 | Review Group II criteria in the full NCD 169 document. The policy summary in this update was truncated at the Group II section. If your practice treats patients who don't clearly meet Group I thresholds, get the complete text from CMS before the effective date and confirm your billing guidelines match. You can access the source at the CMS NCD 169 policy page. |
| 7 | Check your MAC's local coverage determinations. NCD 169 sets the national standard, but your Medicare Administrative Contractor may have issued supplemental LCD guidance that adds documentation requirements or billing guidelines specific to your region. This is general Medicare billing practice — not a requirement stated in NCD 169 itself — but it's worth confirming before the effective date. |
| 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 Oxygen Under NCD 169
This policy update does not include specific CPT, HCPCS, or ICD-10 codes in the published version data. This is common for NCD-level policies, which typically set medical necessity criteria that apply across a range of codes billed by DME suppliers.
For the current applicable HCPCS code list tied to this NCD, check with your MAC or your DME billing team directly. Do not rely on this post for code-level guidance — the source policy contains no enumerated codes.
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