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Updated 2026-05-21

Services & Treatments · A field guide entry

Home oxygen therapy and Medicare coverage: the 2026 rules.

Medicare Part B covers home oxygen therapy when qualifying tests document the need: arterial blood gas with PaO2 of 55 mmHg or lower, or pulse oximetry showing SpO2 of 88% or lower, on room air at rest, during exercise, or during sleep. The supplier rents the equipment for 36 months. After 36 months, the equipment belongs to the patient, and the supplier continues to provide supplies and service for an additional 24 months (60 months total). Patients pay 20% coinsurance during the rental period under Original Medicare.

The four-line answer

What it is
Home oxygen delivered via stationary concentrator, portable concentrator, or compressed/liquid tanks, with associated tubing, cannulas, humidifier when prescribed, and 24-hour service coverage from the supplier.
Who qualifies
A Medicare beneficiary with documented hypoxemia: PaO2 at or below 55 mmHg, or SpO2 at or below 88%, on room air at rest. Borderline values (56 to 59, or 89%) can qualify when paired with specific complicating conditions.
What Medicare covers
Part B DME at 80% coinsurance. 36-month capped rental during which the supplier owns and services the equipment. After 36 months, ownership transfers to the patient and the supplier continues service for 24 additional months.
What Medi-Cal covers
Home oxygen therapy with similar clinical criteria and additional flexibility for portable concentrators and liquid systems, with the 20% coinsurance covered for dual-eligibles.

The simple version

Home oxygen therapy is one of the most cost-effective and life-prolonging interventions for seniors with chronic lung disease and certain cardiovascular conditions. Long-term oxygen for patients with severe COPD is one of the few interventions with mortality benefit in randomized trials. Medicare has covered it since the 1980s, with rules that have grown more specific over time, particularly around qualifying tests and the 36-month rental cap.

The simple version: a qualifying test on room air at rest (or in defined circumstances during exercise or sleep) opens coverage, a Medicare-enrolled supplier delivers the equipment, the supplier rents it to Medicare for 36 months, and ownership transfers to the patient with continued service for an additional 24 months.

The qualifying tests

Coverage hinges on documented hypoxemia. The accepted tests:

The test must be performed on room air (no supplemental oxygen during the measurement) and during a stable medical period (typically not during an acute exacerbation or within 30 days of one). Testing immediately at hospital discharge after acute illness sometimes captures values that do not reflect chronic baseline, which can either qualify or disqualify a patient inaccurately. A re-test 30 to 90 days after recovery often produces a more accurate baseline.

What equipment Medicare covers

Equipment is provided based on the prescription and the supplier’s configuration:

The 36-month cap and what happens after

The 36-month rental rule is one of the most distinctive features of Medicare DME. The supplier rents the equipment for 36 continuous months. During that period the supplier is responsible for delivery, setup, equipment service, repairs, and supply restocking, and the supplier owns the equipment.

After the 36th month, ownership transfers to the patient as owned equipment. The supplier’s obligation shifts: for 24 additional months, the supplier must continue providing supplies (tubing, cannulas, humidifier components, tank refills for ambulatory use) and equipment service at no additional rental charge. After this 60-month total service period, if oxygen is still medically necessary, a new 36-month rental cycle begins with a Medicare-enrolled supplier.

Continued medical necessity must be documented periodically through the rental and post-rental period. Most patients on long-term oxygen continue to qualify, with the prescribing physician confirming the ongoing need.

What it costs in 2026

Under Original Medicare Part B, the patient pays 20% of the monthly oxygen rental:

Medigap typically eliminates the 20% share. Medi-Cal members pay nothing. Medicare Advantage plans use their own copay structures.

Stationary versus portable: matching equipment to the patient

For patients who are largely home-bound, a stationary concentrator plus a small compressed-gas tank for occasional outings is usually adequate and the lowest-cost configuration. For patients who leave the home regularly (clinic visits, family events, walking exercise), a portable oxygen concentrator allows several hours of mobility without tank exchanges. For very active patients who do extended outdoor activity, liquid oxygen historically offered the longest duration, though supplier availability has narrowed.

Pulse-dose POCs deliver oxygen only on inhalation, extending battery life. They suit patients with lower flow requirements (typically 1 to 3 liters-per-minute equivalent). Patients on higher continuous-flow needs may require a portable that supports continuous mode or may need compressed-gas tanks for ambulatory use.

Medi-Cal coverage in California

Medi-Cal covers home oxygen with comparable clinical criteria. The managed-care plan or county Fee-for-Service program handles prior authorization. For dual-eligible members, Medicare pays primary at 80% and Medi-Cal picks up the 20% coinsurance, removing out-of-pocket cost. Medi-Cal sometimes offers more flexibility on portable configurations for members with documented mobility needs that standard Medicare equipment does not adequately address.

For Medi-Cal-only members (members without Medicare), oxygen is covered directly through the plan, with no member cost.

How to start

  1. The patient sees their physician or pulmonologist. The provider orders a qualifying test (ABG or SpO2 on room air, at rest, with consideration of exercise and sleep oximetry when relevant).
  2. If results qualify under one of the criteria, the physician writes a Certificate of Medical Necessity (CMN) and the oxygen prescription, specifying flow rate and use (continuous, intermittent, nocturnal).
  3. The order goes to a Medicare-enrolled oxygen supplier. For competitive-bid metros in California, the supplier must hold a contract for oxygen.
  4. The supplier delivers and sets up the stationary concentrator, trains the patient and family on use, configures portable equipment if prescribed, and establishes the monthly supply schedule. Delivery typically within 1 to 3 business days for non-urgent orders.
  5. The supplier provides 24-hour service coverage for equipment failures during the rental period.

Common misconceptions to clear up

“If my parent feels short of breath, Medicare will cover oxygen.” Symptoms do not qualify. A measured SpO2 of 88% or lower on room air (or one of the other criteria) is what qualifies. Many symptomatic patients have SpO2 in the 90s and do not qualify for home oxygen under Medicare rules.

“The patient owns the concentrator from day one.” No. The supplier owns it during the 36-month rental. Ownership transfers at month 36. Even then, the supplier continues service for 24 more months.

“We can switch suppliers if we are unhappy.” Switching during the 36-month rental is limited to specific circumstances (supplier exits, geographic moves, service failures). Routine preference switches are not allowed during the rental cap.

“After 36 months the oxygen benefit ends.” Equipment ownership transfers to the patient at month 36. Supplies and service from the supplier continue for 24 additional months. If oxygen is still needed at month 60, a new 36-month rental cycle begins.

Related services and next steps

This guide explains coverage and eligibility, not medical advice. Talk to a licensed clinician about care decisions. California Care Compass does not place referrals on Services & Treatments pages.

Common questions

7 entries

When does Medicare cover home oxygen?

Medicare covers home oxygen when qualifying tests document hypoxemia and the prescribing physician confirms it is medically necessary. The primary criteria are: arterial blood gas (ABG) showing PaO2 of 55 mmHg or lower, or pulse oximetry showing SpO2 of 88% or lower, tested on room air at rest. Borderline values (PaO2 56 to 59 or SpO2 89%) qualify when paired with documented complications: pulmonary hypertension, cor pulmonale, or hematocrit above 56%. Testing during exercise or sleep can also qualify in defined cases. The qualifying test must be performed by a Medicare-approved provider, typically while the patient is in a stable medical state (not during an acute exacerbation).

How does the 36-month rental rule work?

Home oxygen is one of the most distinctive items in Medicare's DME benefit. The supplier rents the equipment to Medicare for 36 months. During those 36 months Medicare pays a monthly rate covering the equipment, supplies (tubing, cannulas, humidifier when prescribed), and service. After the 36th month, the equipment belongs to the patient. The supplier is then required to continue providing supplies and service for an additional 24 months at no additional rental charge, for a total service period of 60 months. The patient pays 20% coinsurance during the rental, with Medigap or Medi-Cal often covering it.

Stationary or portable: what does Medicare cover?

Medicare covers both, but with different rules. Stationary equipment (a home concentrator that runs continuously) is the baseline and is included in the standard monthly rental. Portable equipment for use outside the home is covered as an add-on when the patient is mobile, leaves the home regularly, and would benefit from continuous oxygen. The portable add-on increases the monthly rental. Portable options include compressed-gas tanks, liquid oxygen reservoirs, and portable oxygen concentrators (POCs). The specific equipment provided depends on the supplier and the prescription.

What does the patient pay in 2026?

Under Original Medicare Part B, the patient pays 20% coinsurance on the monthly oxygen rental after meeting the Part B deductible. Typical monthly rentals: stationary concentrator alone around $180 to $220 per month, with patient share roughly $36 to $44 before Medigap. Adding portable equipment raises the monthly rental by $30 to $80 with corresponding patient share. Medigap eliminates the 20% share. Medicare Advantage uses plan-specific copays. Medi-Cal members pay nothing. After the 36-month cap, equipment is owned by the patient and supplies/service from the supplier continue for 24 months at the same effective patient cost structure for supplies.

What happens after the 60-month service period ends?

After 60 total months (36 rental plus 24 post-cap service), the patient's relationship with that supplier ends. If oxygen is still medically necessary, the patient must start a new 36-month rental cycle with a Medicare-enrolled supplier. The supplier can be the same one (often it is) or a different supplier. Re-qualification typically does not require a new ABG or SpO2 test if oxygen has been continuously used and the prescribing physician confirms the ongoing need. The new rental cycle pays for new equipment delivered, beginning a fresh 36-month rental period.

Can the patient switch suppliers during the rental?

During the 36-month rental period, the patient is generally tied to the original supplier unless specific circumstances allow a transfer (the supplier exits the market, the patient moves to a service area the original supplier does not cover, the supplier fails to provide adequate service). CMS allows transfers in these circumstances, but routine switching for preference reasons is not allowed during the rental cap. After the 36-month cap, when supplies and service continue for 24 more months, the supplier is still required to serve the patient. Patients who travel between regions of California may need supplier coordination for portable refills.

How does Medi-Cal compare?

Medi-Cal covers home oxygen with similar clinical criteria to Medicare. For dual-eligible members, Medicare pays first at 80% and Medi-Cal picks up the 20% coinsurance, leaving no out-of-pocket cost. For Medi-Cal-only members (those who do not have Medicare), Medi-Cal covers oxygen directly through the managed-care plan or county Fee-for-Service program. Medi-Cal sometimes offers more flexibility on portable concentrators and liquid oxygen systems for members who need higher mobility. Prior authorization is handled by the plan.

Sources

  1. 01Centers for Medicare & Medicaid Services · Oxygen equipment and accessories coverage · accessed 2026-05-21
  2. 02Centers for Medicare & Medicaid Services · National coverage determination: home use of oxygen (240.2) · accessed 2026-05-21
  3. 03Noridian Healthcare Solutions · Oxygen and oxygen equipment policy article (California DME MAC) · accessed 2026-05-21
  4. 04Centers for Medicare & Medicaid Services · Oxygen 36-month cap and post-cap supplier obligations · accessed 2026-05-21
  5. 05California Department of Health Care Services · Medi-Cal durable medical equipment benefit · accessed 2026-05-21
  6. 06American Thoracic Society · Home oxygen therapy clinical guidelines · accessed 2026-05-21
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