Medicare Coverage for Hyperbaric Oxygen Therapy: 15 Conditions and Costs

Medicare coverage for hyperbaric oxygen therapy is limited to 15 specific medical conditions, and only when the treatment is delivered inside a pressurized chamber that surrounds your whole body. The rules come from a national policy called NCD 20.29. If your diagnosis is on the list and your records support medical necessity, Part B pays 80% of the approved amount after you meet the annual deductible. If your diagnosis is not on the list, Medicare will not pay, no matter what your doctor recommends.

The 15 Conditions That Qualify

The CMS National Coverage Determination lists every condition eligible for coverage. The therapy must be given in a chamber (single-person or multi-person) and must supplement standard medical care rather than replace it. The approved conditions are:

Acute carbon monoxide poisoning
Decompression illness
Gas embolism
Gas gangrene
Acute traumatic peripheral ischemia, when loss of limb or function is threatened
Crush injuries and reattachment of severed limbs
Progressive necrotizing infections, such as necrotizing fasciitis
Acute peripheral arterial insufficiency
Compromised skin grafts and flaps (not for primary wound management)
Chronic refractory osteomyelitis, unresponsive to conventional treatment
Osteoradionecrosis
Soft tissue radionecrosis
Cyanide poisoning
Actinomycosis, only when antibiotics and surgery have failed
Diabetic wounds of the lower extremities, with additional criteria

If your condition is not on this list, Medicare will deny the claim. No national exceptions exist, though your regional Medicare Administrative Contractor may issue supplemental guidance on documentation for the listed conditions.¹

Extra Rules for Diabetic Wounds

Diabetic foot wounds are the most common reason people seek HBOT under Medicare, and this is the hardest category to get approved. You must meet all three of these criteria:

You have type I or type II diabetes, and the wound on your lower extremity is caused by the disease.
The wound is classified as Wagner grade III or higher, meaning a deep ulcer with bone infection, abscess, or significant tissue destruction.
You completed at least 30 consecutive days of standard wound therapy with no measurable improvement.

That last requirement is where most claims fail. “Standard wound therapy” has a specific meaning under NCD 20.29. Your medical record must show that your care team did all of the following before HBOT was prescribed:

Assessed blood flow in the affected limb and corrected vascular problems where possible
Optimized your nutritional status
Brought your blood sugar under control
Removed dead tissue through debridement
Kept the wound bed clean and moist with appropriate dressings
Used proper off-loading to reduce pressure on the wound
Treated any infection present

If any of these steps is missing from the chart, Medicare can deny the claim on the grounds that standard wound therapy was not truly exhausted.¹

Coverage Can Stop Mid-Treatment

Getting approved to start HBOT does not guarantee open-ended coverage. Your wound must be formally evaluated at least every 30 days. If there are no measurable signs of healing in any 30-day window, Medicare stops paying for continued sessions. This rule applies no matter how many treatments you have already completed or how much progress you made earlier.¹

There is no hard cap on total sessions in the NCD. Coverage simply continues as long as the wound keeps improving in each window. Ask your provider to document wound measurements, photographs, and clinical assessments at every evaluation. That documentation is what protects your continued coverage.

Conditions Medicare Will Not Pay For

NCD 20.29 names a list of conditions explicitly excluded from coverage, even though patients often ask about them:

Pressure ulcers, skin ulcers, and stasis ulcers
Multiple sclerosis
Senility
Alzheimer’s disease, Pick’s disease, and other nonvascular causes of chronic brain syndrome
Stroke recovery
Cerebral palsy
Autism spectrum disorder

Anything not on the approved list is non-covered; the exclusions above are just the ones patients most often ask about. CMS has determined that the clinical evidence does not support HBOT for these diagnoses.¹

One related point of confusion: topical oxygen therapy, in which oxygen is applied only to the wound surface, is not the same thing as HBOT. CMS removed the national exclusion for topical oxygen from NCD 20.29 in April 2017 and left that coverage decision to regional Medicare Administrative Contractors. Whether topical oxygen is covered for your wound depends on where you live.²

Prior Authorization in Illinois, Michigan, and New Jersey

CMS runs a prior authorization model for non-emergent HBOT in three states: Illinois, Michigan, and New Jersey. Providers in those states must submit a prior authorization request and receive approval before delivering treatment. Michigan started in April 2015; Illinois and New Jersey followed in August 2015.³

Emergency conditions, including carbon monoxide poisoning, decompression illness, and gas embolism, are not subject to prior authorization and can be treated immediately. Outside these three states, there is no national prior authorization requirement, but a Medicare Advantage plan may impose its own.

What You Will Pay

HBOT falls under Medicare Part B as an outpatient service. You pay the standard Part B cost-sharing: a $283 annual deductible in 2026, then 20% of the Medicare-approved amount for each session. Medicare pays the remaining 80%.⁴⁵

HBOT courses often run dozens of sessions, so the 20% adds up fast. A Medigap policy, Medicare Advantage plan, or retiree insurance may cover the coinsurance and deductible. Many Medigap plans pay the full 20%. Expect two bills per session in some settings: one from the facility for the chamber and staff, and one from the supervising physician.

If your provider thinks Medicare is likely to deny your claim, you must receive an Advance Beneficiary Notice before treatment starts. The ABN warns you that Medicare may not pay and asks whether you want to proceed anyway. Read it carefully. If you sign it and the claim is denied, the bill is yours.⁶

Appealing a Denied HBOT Claim

HBOT claims are denied more often than many outpatient services, usually for documentation gaps, a wound that does not meet the Wagner grade threshold, or thin evidence that standard wound care actually failed. You have the right to appeal, and for a treatment this expensive, the effort is often worth it.

Medicare has five levels of appeal, and most cases end in the first two:

Level 1, Redetermination: file a written request with your Medicare Administrative Contractor within 120 days of the denial. The MAC generally decides within 60 days.
Level 2, Reconsideration: if the MAC denies, you have 180 days to ask a Qualified Independent Contractor to review. Decision within 60 days.
Level 3, Administrative Law Judge hearing: within 60 days of the QIC decision, request a hearing before the Office of Medicare Hearings and Appeals. Target decision within 90 days.
Level 4, Medicare Appeals Council: within 60 days of the OMHA decision, request Council review. Target 90 days.
Level 5, Federal court: for claims meeting the minimum dollar threshold ($1,960 in 2026), file within 60 days of the Council’s decision.

At Level 1, focus on fixing whatever caused the denial. If standard wound care documentation was missing, get your doctor to submit the records. If the wound was not classified at the right Wagner grade, ask your provider to review and correct the clinical notes. A first denial is often a paperwork problem, not a final answer.⁷

1
Centers for Medicare & Medicaid Services. National Coverage Determination – Hyperbaric Oxygen Therapy
2
Centers for Medicare & Medicaid Services. National Coverage Analysis – Hyperbaric Oxygen Therapy
3
Centers for Medicare & Medicaid Services. Non-Emergent Hyperbaric Oxygen Therapy Prior Authorization Model Frequently Asked Questions
4
Medicare.gov. Hyperbaric Oxygen Therapy
5
Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
6
Centers for Medicare & Medicaid Services. Advance Beneficiary Notice of Noncoverage
7
Medicare.gov. Appeals in Original Medicare