Hyperbaric Oxygen (HBO) Therapy

Hyperbaric Oxygen (HBO) therapy is a modality covered under Medicare in which the entire body is exposed to oxygen under increased atmospheric pressure. Program reimbursement for HBO is limited to services administered in a chamber.

On this page, view the following related information:


The CMS HBO National Coverage Determination (NCD) 20.29 lists the indications and limitations of coverage.

HBO therapy is a valuable adjunctive treatment used in combination with accepted standard therapeutic measures when loss of function, limb, or life is threatened. HBO is indicated within the first 4-6 hours of the acute event, and only after documented restoration of the blood circulation. For reperfusion injuries, crush injuries or pending compartment syndrome, therapy beyond 2-3 days has not shown beneficial salvage or further limit to loss of tissue or limb.

Documentation must support no measurable sign of healing for 30 days prior to starting HBO including wound measurements prior to the initiation of HBO and wound measurements after HBO. Continued treatment with HBO therapy is not covered if measurable signs of healing have not been demonstrated within any 30-day period of treatment.

Noncovered Conditions

No program payment may be made for any conditions other than those listed in NCD 20.29 under A. Covered Conditions.

Documentation Requirements

Diabetic wound(s)

  • Wagner grade classification (must be Wagner grade III or higher) with diagnostic testing to support Wagner grade
  • Patient has type 1 or type 2 diabetes and has lower extremity wound due to diabetes
    • NCD does not cover surgical or injuries complicated by diabetes
  • Documentation supporting prior failed treatment using standard wound care
  • Documentation supporting there were no measurable signs of healing for at least 30 consecutive days of treatment when using standard wound therapy
  • Evaluation of wound at least every 30 days during administration of HBO therapy that supports evidence of measurable signs of healing

Standard Diabetic Wound Care Therapy Prior to Starting HBO

  • Assessment of patient's vascular status and correction of problems, if applicable
  • Support of optimization of nutritional status
  • Support of optimization of glucose control
  • Support of debridement of the devitalized tissue
  • Support of wound care management that includes maintenance of a clean, moist bed of granulated tissue with appropriate moist dressing
  • Support of appropriate off-loading
  • Support of treatment to resolve infection

The documentation submitted to a review entity should support the diagnosis used with HBO therapy. Clearly support wound measurements/assessments by providing documentation before and during HBO therapy.

Billing and Coding

Facility Services - UB-04 or electronic equivalent

Type of Bill (TOB)
  • 0111, 0131, 0851
Revenue Code Applicable
  • 0413 respiratory services
  • G0277 HBO under pressure, full body chamber, per 30-minute interval
    • Medically Unlikely Edits (MUE) apply - five units per date of service based on clinical benchmarks
  • Add time for all processes included in treatment: descent, air breaks and ascent
    • 46-75 minutes = 2 units
    • 76-105 minutes = 3 units
    • 106-135 minutes = 4 units


Physician Services - CMS-1500 Claim Form

  • 99183 - Physician or other qualified health care professional attendance and supervision per session
    • MUE apply
  • Physician attendance and supervision of HBO therapy (CPT 99183) includes evaluation and management (E&M) services related to HBO therapy


Tips and Additional Information

  • Calculate total number of 30-minute intervals billable under HCPCS G0277
    1. Time spent by patient under 100% oxygen
    2. Time for descent
    3. Time for air breaks and
    4. Time for ascent
  • Additional units may be billed for sessions requiring at least 16 minutes of next 30-minute interval
  • Providers can appeal a denial if date of service exceeds five units. Documentation submitted must support units of service in excess were reasonable and necessary
  • Radionecrosis: Avoid denials. Send documentation to support diagnosis or to support that radiation therapy was at least six months prior to wound development
  • E&M services integral to HBO therapy include, but are not limited to, updating history and physical, examining patient, reviewing laboratory results and vital signs with special attention to pulmonary function, blood pressure, and blood sugar levels, clearing patient for procedure, monitoring and/or assisting with patient positioning, evaluating and treating patient for barotrauma and other complications, prescribing appropriate medications, etc.
  • Physician may report E&M services performed on same date of service of HBO with modifier 25, if a physician performs unrelated, significant, and separately identifiable services
  • Medicare coverage of topical oxygen for treatment of chronic wounds will be determined by local Medicare Administrative Contractors (MACs)
  • NCD lists non-covered items and services, such as cutaneous, decubitus, and stasis ulcers. Locate NCD for full list



Last Updated Dec 09 , 2023