Medicare covers portable oxygen concentrators, but only if a doctor prescribes them and you meet specific medical requirements

Medicare Part B covers durable medical equipment (DME), which includes portable oxygen concentrators. The device must be prescribed by your doctor, and you must have a medical condition that requires supplemental oxygen — most commonly COPD, pulmonary fibrosis, or severe heart disease. Medicare will not cover a concentrator straightforward because you want one or because you use oxygen occasionally.

You pay 20 percent of the approved amount after you meet your Part B deductible. The supplier you choose must be enrolled with Medicare. If you rent rather than buy, the rental payments count toward the purchase price, and ownership transfers to you once you have paid the full cost.

Key Takeaways

  • Your doctor must write a prescription stating that you need supplemental oxygen and specify the flow rate and hours per day you require it.
  • Medicare covers both purchase and rental of portable concentrators through enrolled DME suppliers, and you pay 20 percent of the approved amount after your deductible.
  • A portable concentrator is covered only if you also have a stationary concentrator at home — Medicare does not cover portables as your sole oxygen source.
  • The supplier must obtain prior authorization from Medicare before delivering the equipment, which typically takes one to two weeks.
  • If you switch suppliers or the equipment fails, you may face delays in getting a replacement unless you understand Medicare's rules about equipment ownership and transfers.

What your doctor's prescription must include

Your doctor cannot straightforward write "patient needs oxygen." Medicare requires the prescription to state the specific flow rate (measured in liters per minute), the number of hours per day you need oxygen, and whether you need it during rest, exertion, or both. The prescription must also document the medical reason — the diagnosis that makes oxygen medically necessary.

If your doctor has not prescribed oxygen in writing, ask them to do so before you contact a supplier. Suppliers cannot order equipment without this documentation, and Medicare will deny the claim if the prescription is missing or incomplete. Some doctors' offices send prescriptions directly to suppliers; others give you a copy to deliver yourself.

How to find a Medicare-enrolled DME supplier

Not every medical supply company is enrolled with Medicare. You can search for enrolled suppliers in your area using the Medicare Supplier Directory at dmepos.cms.gov. Enter your ZIP code and select "oxygen concentrator" as the equipment type. The directory shows which suppliers are currently active and whether they have any compliance issues on record.

You can use any enrolled supplier you choose — Medicare does not assign you to one. Some people use the supplier their doctor recommends, while others compare prices or service records. Call at least two suppliers and ask what they charge for the specific model your doctor prescribed, what rental or purchase options they offer, and how quickly they can deliver.

Rental versus purchase: what Medicare pays

Medicare allows you to either rent or buy a portable concentrator. If you rent, you pay a monthly fee, and the supplier owns the equipment. Once your cumulative rental payments reach the purchase price (usually between $1,500 and $3,000 depending on the model), ownership transfers to you and rental stops. You then own the concentrator outright.

If you buy outright, you pay the full purchase price upfront (minus your 20 percent coinsurance). Some people buy because they want to own the equipment when ready; others rent because they prefer to spread the cost over time and avoid the upfront expense. Medicare pays the same total amount either way — the difference is timing and who holds the equipment while you are paying.

After you own the concentrator, Medicare covers repairs and replacement parts through the supplier for five years from the date of delivery. After five years, you own the equipment but Medicare no longer covers maintenance.

The prior authorization process and what causes delays

Before the supplier delivers a concentrator, they must obtain prior authorization from Medicare. This means the supplier submits your prescription and medical documentation to Medicare for review. Medicare checks that your doctor's prescription meets their requirements and that you have not already received a portable concentrator in the past five years.

Prior authorization typically takes five to ten business days. Some suppliers can expedite this to two to three days if your situation is urgent — for example, if you are being discharged from a hospital and need oxygen when ready. Tell the supplier if you need the equipment quickly, and ask them to request expedited review.

Authorization can be delayed or denied if your prescription is incomplete, if your doctor's office does not respond to Medicare's request for additional information, or if Medicare determines the equipment is not medically necessary based on your diagnosis. If authorization is denied, you have the right to appeal. The supplier can help you file an appeal, or you can contact Medicare directly at 1-800-MEDICARE.

Your out-of-pocket costs and what affects them

You pay 20 percent of Medicare's approved amount for the concentrator, after you have met your Part B deductible ($240 in 2024, though this amount changes yearly). The approved amount varies by region and supplier, but Medicare sets a maximum allowable charge. You cannot be charged more than this amount, even if the supplier's list price is higher.

If you have a Medigap or Medicare Advantage plan, your out-of-pocket costs may be lower. Medigap plans often cover the 20 percent coinsurance. Medicare Advantage plans vary — some cover DME with a copay, others with coinsurance. Check your plan documents or call your plan to find out what you will owe.

If you rent and later own the concentrator, your monthly rental payments count toward the purchase price. Once you own it, you have no further monthly payments to Medicare, though you remain responsible for any repairs not covered by Medicare after the five-year warranty period.

Common reasons Medicare denies portable concentrator claims

The most frequent reason for denial is that the patient does not have a stationary concentrator at home. Medicare covers portable concentrators only as a supplement to a stationary unit, not as a replacement. If you only need oxygen when you leave the house, Medicare may determine that a portable is not medically necessary and deny the claim.

A second common reason is an incomplete or outdated prescription. If your doctor prescribed oxygen more than one year ago and has not renewed the prescription, Medicare may request an updated one. If your doctor's prescription does not specify the flow rate or hours per day, Medicare will ask for clarification before approving.

A third reason is prior equipment within five years. If you received a portable concentrator from Medicare within the past five years, Medicare will not cover another one unless your medical condition has significantly worsened and your doctor documents this change.

What happens if you switch suppliers or need a replacement

If you are renting from one supplier and want to switch to another, the new supplier can take over your rental agreement. Your previous rental payments still count toward the purchase price with the new supplier. However, there may be a gap of a few days while the new supplier obtains authorization and arranges delivery.

If your concentrator breaks and is under warranty (within five years of delivery), the supplier must repair or replace it at no cost to you. If the equipment is damaged by misuse or accident, Medicare may not cover the replacement. If the concentrator is older than five years and breaks, you own it but Medicare will not cover repairs — you can pay out of pocket or purchase a new one.

If you need a replacement concentrator before five years have passed because your medical condition has worsened, your doctor must document the change and request a new prescription. Medicare will then authorize a replacement, and you will pay the 20 percent coinsurance again.

Frequently Asked Questions

Can I use a portable concentrator without a stationary one at home?

No. Medicare covers portable concentrators only if you also have a stationary concentrator for home use. If you need oxygen only when traveling or outside the house, Medicare will likely deny the claim. Talk to your doctor about whether a portable is medically necessary for your situation.

What if my doctor prescribed oxygen but I do not have a current prescription in writing?

Contact your doctor's office and ask them to issue a written prescription that includes the flow rate, hours per day, and medical reason. Do not contact a supplier until you have this in hand. The prescription must be dated within the past year for Medicare to accept it.

How long does it take to get a portable concentrator after I order one?

Prior authorization takes five to ten business days. Once authorized, the supplier typically delivers within three to seven days. In urgent cases, some suppliers can expedite authorization to two to three days. Total time from order to delivery is usually two to three weeks.

Do I have to use the supplier my doctor recommends?

No. You can choose any Medicare-enrolled supplier. Your doctor's recommendation is helpful, but you are free to compare suppliers, ask about their service record, and choose based on price, location, or customer reviews. Use the Medicare Supplier Directory to confirm any supplier is enrolled before contacting them.

What if Medicare denies my claim?

You have the right to appeal. The supplier can help you file an appeal, or you can contact Medicare at 1-800-MEDICARE. Most appeals require your doctor to provide additional documentation explaining why the portable concentrator is medically necessary. The appeal process typically takes 30 to 60 days.