Does Medicare cover portable oxygen concentrators? Costs, rental rules, and how to switch suppliers

Short answer

Yes. Medicare Part B covers portable oxygen concentrators as durable medical equipment when blood gas testing confirms low oxygen levels and your doctor prescribes the device. You pay the 2026 Part B deductible of $283, then 20% of the Medicare-approved amount. Oxygen rental works differently from other DME: Medicare pays for 36 months, then the supplier services the equipment for 24 additional months, and after 5 years you get new equipment. Ownership never transfers.

Who qualifies: blood gas testing and qualifying conditions

Medicare uses arterial blood gas testing to decide who qualifies for oxygen equipment. Two thresholds qualify you:

• Blood gas PaO2 of 55 mmHg or lower, measured from an arterial sample.
• Or oxygen saturation (SpO2) of 88% or lower, measured by pulse oximetry.

Testing can be done at rest, during sleep, or during exercise, and where the test is done matters (see the portable-vs-stationary section below). A qualified provider must perform and interpret the test; a store-bought pulse oximeter reading is not enough for Medicare.

There is also a second qualification pathway with slightly less severe blood gas values, but only when specific comorbidities are documented. A PaO2 of 56-59 mmHg or SpO2 of 89% can qualify if the medical record also documents at least one of: dependent edema suggesting congestive heart failure, pulmonary hypertension or cor pulmonale, or erythrocytosis with hematocrit above 56%. If your blood gas result is borderline but you have one of these conditions, ask your doctor to document it, you may still qualify under this second-tier pathway.

Beyond the blood gas thresholds, Medicare recognizes these clinical conditions as qualifying:

• Chronic obstructive pulmonary disease (COPD), the most common qualifying diagnosis.
• Pulmonary fibrosis and other interstitial lung diseases.
• Advanced congestive heart failure with documented low oxygen.
• Cystic fibrosis, bronchiectasis, and other chronic hypoxemic conditions.
• Cluster headaches, a non-blood-gas qualifying condition, when documented by a specialist.

The doctor’s note must document not just the diagnosis but the specific test results, the equipment prescribed (concentrator, tanks, or liquid oxygen), the flow rate in liters per minute, and the duration required per day.

Portable vs. stationary: how to qualify for a POC

This is where the majority of portable oxygen claims fall apart. Medicare defaults to a stationary concentrator plus refillable tanks unless the medical record documents a mobility need for a portable oxygen concentrator (POC).

The path Medicare takes depends on which test qualified you. A sleep-only test qualifies you for stationary equipment only, the coverage rule explicitly excludes portable oxygen when the qualification came from sleep testing. A rest-only test can support portable coverage, but only if the medical record separately documents that you are mobile within your home; without that mobility documentation, expect stationary-only. The clearest path to a portable unit is an exertion-based test, typically while walking on a treadmill or completing a six-minute walk test, that shows your oxygen drop while active.

Practical implication: when you talk to your doctor, ask specifically for a “with-exercise” or “during exertion” blood gas study if you need a portable unit. The exertion test is the strongest single piece of documentation for POC coverage.

Once you qualify for a POC, the supplier chooses which specific model to provide based on your prescribed flow rate. Medicare does not let you pick a specific brand or model, the supplier makes the selection from Medicare-approved units that match your prescription.

The 36-month rental rule (different from other DME)

Oxygen equipment does not follow the standard 13-month capped rental that applies to CPAP, hospital beds, and wheelchairs. The rules here are unique to oxygen:

• Months 1 through 36: Medicare pays the supplier a monthly rental fee. You pay the 20% coinsurance after the annual deductible.
• Months 37 through 60: the supplier is legally required to keep servicing your equipment for 24 more months at no additional payment from Medicare. The supplier provides maintenance, replacement parts, and continuing supplies during this stretch.
• After month 60 (5 years total): the supplier is no longer obligated to continue service. At this point, you start over with new equipment from a supplier of your choice, the 36-month clock restarts.

Ownership never transfers to you. Unlike the CPAP or the wheelchair, you do not own the oxygen equipment at the end of the rental. It belongs to the supplier throughout the 5-year cycle. This is a critical difference many clients only learn about when they try to switch suppliers or ask about upgrading equipment.

What Medicare pays vs. what you pay

Portable oxygen concentrators fall under Medicare Part B, which uses an 80/20 cost split after the annual deductible.

• Part B deductible (2026): $283 for the year, paid once regardless of how many DME items you use.
• Coinsurance (2026): 20% of the Medicare-approved monthly rental amount. Medicare pays the other 80%.
• Medigap: Plans G and F typically pay the 20% coinsurance in full. Plan G is the most common newer purchase; Plan F is available only to those eligible for Medicare before January 1, 2020.
• Medicare Advantage plans: Cost-sharing varies by plan. Most plans must offer at least what Original Medicare covers, but may have different prior-authorization rules and supplier networks.

Typical out-of-pocket during the rental period (approximate, before Medigap):

• Monthly rental coinsurance: $30 to $60 during months 1-36, depending on the equipment type and region.
• Supplies (tubing, cannulas): included in the monthly rental payment during months 1-36. No separate charge.
• Maintenance visits during months 37-60: a small coinsurance may apply for periodic in-home service visits.

With Medigap Plan G or F, most clients pay $0 out of pocket for the equipment and supplies once the deductible is met.

How to get a Medicare-covered POC: step by step

Five steps. Most delays and denials happen at step 2 (blood gas testing) or step 4 (supplier selection).

Step 1, Consult with a pulmonologist or respiratory specialist. For portable oxygen coverage specifically, Medicare expects a specialist referral, not just a primary-care request. The specialist evaluates your symptoms, orders the blood gas study, and writes the prescription.

Step 2, Blood gas study, including exertion testing for POC coverage. As covered above, the test must include a walking or exertion component if you want a portable unit. Ask the ordering clinician to confirm the test protocol before you go.

Step 3, Prescription and Certificate of Medical Necessity. The doctor writes the prescription, which for oxygen equipment includes a Certificate of Medical Necessity (CMN) with specific fields: your diagnosis, the qualifying blood gas result, the prescribed flow rate in liters per minute, the duration of use per day (for example, “continuous” or “with exertion only”), and the type of equipment.

Step 4, Choose a Medicare-enrolled DME supplier. Only accredited, Medicare-enrolled suppliers can bill Medicare for oxygen equipment. Use the directory at medicare.gov/care-compare, filtering by durable medical equipment in your zip code. Ask three questions before you commit: “Do you accept assignment?” (locks in the Medicare-approved amount as the price), “Do you provide portable units on your Medicare formulary?” (some suppliers focus on stationary only), and “What happens at month 60, do you help transition to a new supplier?”

Step 5, Delivery, setup, and the 36-month rental begins. The supplier delivers the equipment, trains you on flow rate settings and cleaning, and provides a starter set of tubing and cannulas. The rental clock starts on delivery day.

The supplier lock-in problem (and how to switch)

Oxygen equipment has a supplier-switching problem that other DME categories do not. Because the equipment belongs to the supplier and the 36-month rental period is a single continuous commitment, switching mid-rental is difficult. Other suppliers are not legally required to accept a transfer of your care in the middle of a 36-month period.

Practical steps if you need to switch (moving, poor service, supplier going out of business):

1. Identify a willing new supplier before you leave the current one. Call several Medicare-enrolled suppliers in your area and ask specifically: “Will you accept a mid-benefit transfer for oxygen equipment?” Most will only say yes if you have grounds, poor service, moving out of area, or the current supplier is closing.
2. Coordinate the handoff date. The new supplier delivers equipment on the same day the old one picks up its equipment. There should be no gap in oxygen access.
3. Confirm equipment compatibility. Not all POC models deliver the same flow-rate range. Your prescription may need updating if the new supplier’s units are different.
4. Get an updated prescription. The new supplier will typically ask for a current Certificate of Medical Necessity. If yours is older than a year, expect the doctor to update it.
5. Document the reason for the switch. If the current supplier disputes the transfer or Medicare questions it, having a written record (service complaints, move confirmation, supplier closure notice) protects you.

If your current supplier goes out of business, Medicare directly assists with finding a replacement. Call 1-800-MEDICARE for supplier-of-last-resort guidance.

What if Medicare denies your oxygen claim?

Denials happen most often for four reasons: the blood gas testing did not include the exertion component (portable coverage denied, stationary offered instead), the physician documentation was incomplete (missing flow rate, missing duration, or ambiguous diagnosis), the supplier was not enrolled or accredited, or the certificate of medical necessity was outdated at the time of billing.

If you receive a denial:

1. Read the denial notice carefully. Look for the specific reason code and what documentation Medicare wants.
2. Ask your doctor to add to the record. Most denials are fixable by ordering the missing test (for example, the exertion blood gas study) or updating the certificate of medical necessity.
3. File a redetermination within 120 days. You have 120 days from the date on the Medicare Summary Notice to file the first-level appeal. Include additional documentation and the odds of reversal are meaningful.
4. Get help. Free help is available from your State Health Insurance Assistance Program (SHIP) at shiphelp.org, and the Medicare Rights Center at 1-800-333-4114. For end-to-end handling, that is what a patient advocate does.

For a full walkthrough of the appeal process, see our Medicare denial appeal guidance.

How Baba helps

Oxygen coverage denials cluster in two places: incomplete testing (the blood gas study wasn’t done with the exertion component Medicare requires for portable coverage) and incomplete documentation (the certificate of medical necessity is missing flow rate, duration, or specific equipment fields). Baba advocates work both gaps before the claim gets submitted: they help schedule the pulmonologist consult, confirm the test protocol includes the exertion component if you need a portable unit, review the certificate of medical necessity against Medicare’s field requirements, and verify the supplier’s Medicare enrollment and accreditation.

If you are already past a denial, Baba prepares and files the redetermination, coordinates the additional testing or documentation with your doctor’s office, and tracks the response deadline. Baba also handles supplier switching mid-rental, identifying willing new suppliers, coordinating the handoff, and documenting the reason for the transfer.

Baba provides care navigation and advocacy for clients dealing with these issues. Talk to Baba to learn what support may be available.