If you have COPD, pulmonary fibrosis, or another condition causing chronically low blood oxygen, Medicare Part B may cover your home oxygen equipment — but only after you meet specific medical criteria. Here's exactly what you need to know.
Who Qualifies for Medicare Home Oxygen Coverage?
Medicare covers home oxygen therapy under Part B when you have documented chronic hypoxemia — abnormally low blood oxygen levels that persist even while you're resting. Qualifying requires one of these documented test results:
- Arterial blood gas (ABG) test: PO₂ at or below 55 mmHg, OR oxygen saturation at or below 88%
- Pulse oximetry: SpO₂ at or below 88% — but note that oximetry results must be confirmed in specific circumstances
- Higher thresholds apply if you also have pulmonary hypertension, cor pulmonale, erythrocythemia, or nocturnal hypoxemia — qualifying oxygen levels are then PO₂ 56–59 mmHg or SpO₂ 89%
Your doctor must conduct or order these tests and document the results in your medical record. Without lab-confirmed hypoxemia meeting Medicare's criteria, your claim will be denied.
What Home Oxygen Equipment Does Medicare Cover?
Medicare Part B covers the full range of home oxygen delivery systems when medically necessary:
- Stationary oxygen concentrators — electric units that extract oxygen from room air; most common for home use
- Portable oxygen concentrators (POCs) — battery-powered units for mobility; covered under certain conditions
- Liquid oxygen systems — for patients requiring very high flow rates
- Compressed gas tanks — cylinder-based systems for backup or portable use
- Accessories: nasal cannulas, tubing, masks, and humidifier bottles are included
The specific system prescribed depends on your prescribed flow rate, activity level, and oxygen needs as documented by your physician.
The 36-Month Rental Rule — and What Happens After
Home oxygen follows Medicare's capped rental system, but with a longer timeline than most DME. Medicare pays your supplier to rent you the equipment for 36 months of continuous use. After 36 months:
- The supplier must continue providing oxygen contents (gas or liquid) and maintenance for an additional 24 months at no charge
- After the full 60-month period, Medicare re-evaluates coverage based on continued medical need
- You do not receive ownership of the equipment the way you do with CPAP after 13 months
This means your supplier has a contractual obligation to maintain your equipment and deliver oxygen for five full years before coverage cycles.
What Does Medicare Pay — and What Do You Owe?
Once you've met your annual Part B deductible ($257 in 2026), Medicare pays 80% of the approved monthly rental amount for oxygen equipment. You're responsible for the remaining 20% coinsurance.
If you have a Medigap (Medicare supplement) plan, it typically covers the 20% coinsurance, meaning your out-of-pocket cost could be zero. Medicare Advantage plans cover oxygen as well, but may have different cost-sharing structures and require you to use network suppliers.
How to Get Your Oxygen Covered: Step-by-Step
- Get tested: Your doctor orders an ABG or pulse oximetry test to document your qualifying oxygen levels
- Obtain a certificate of medical necessity (CMN): Your doctor completes this form documenting your diagnosis, oxygen flow rate, and hours per day of use
- Choose a Medicare-enrolled supplier: The supplier must be enrolled in Medicare and CMS-accredited. Non-accredited suppliers cannot bill Medicare
- Provide the CMN to your supplier: They submit the paperwork to Medicare on your behalf
- Begin rental: Equipment arrives, the 36-month rental clock starts
Why Medicare Denies Oxygen Claims — and How to Prevent It
Oxygen is one of Medicare's most-denied DME categories. Common reasons for denial include:
- Qualifying blood gas levels not properly documented
- Test conducted while the patient was acutely ill (levels must reflect a stable chronic condition)
- Certificate of Medical Necessity incomplete or missing
- Supplier not enrolled in Medicare
- Oxygen ordered for a non-qualifying condition (mild or moderate COPD without meeting hypoxemia criteria)
The most reliable prevention: have your doctor complete the CMN carefully and ensure the qualifying test is conducted when you're in a stable, non-acute state.
Portable Oxygen Concentrators: Special Considerations
Portable oxygen concentrators are popular for patients who want mobility. Medicare covers POCs, but the flow rate must match your prescription. Most POCs deliver oxygen in pulse-dose mode (triggered by your breath), which isn't suitable for all patients. If you need continuous-flow oxygen at rest, your supplier will need to provide a stationary concentrator plus a POC for activity — or an alternative portable system.
What to Do Next
If you or a family member has COPD, pulmonary fibrosis, heart failure, or another condition affecting breathing, talk to your doctor about whether a qualifying blood gas test is appropriate. Starting the documentation early means you're not scrambling for equipment during a hospitalization or acute episode.
When you're ready to find a supplier, search our directory of Medicare-approved oxygen suppliers to find accredited providers near you. Every supplier listed accepts Medicare and can verify whether they cover your area and equipment needs.