ModifiedCignaPolicy 0053

Hyperbaric and Topical Oxygen Therapy

This Cigna Coverage Policy governs medical necessity and coverage determinations for systemic hyperbaric oxygen therapy (HBO/HBOT/HOT) in single or multiplace chambers and topical oxygen therapy (TOT), including indications considered medically necessary, adjunctive, or not medically necessary, for members under Cigna-administered plans.

Policy Summary

PayerCigna

PolicyHyperbaric and Topical Oxygen Therapy

Policy CodePolicy 0053

Change TypeCoverage status updates (TOT & select indications)

Effective DateSep 15, 2025

Next Review DateMay 15, 2026

Key ActionDocument that a diabetic foot ulcer failed to heal with optimal standard of care before requesting topical oxygen therapy as adjunctive treatment.

SourceLink

POLICY UPDATE CHANGES

Changed from not covered to covered: topical oxygen therapy as adjunct treatment for a diabetic foot ulcer that has failed to heal with optimal standard of care.

Changed from not covered to covered: avascular necrosis.

Added not covered: penile glans necrosis.

Annual review with no clinical policy statement changes.

2025-09-15most recent focused review date

2025-05-15annual review with changes

A4575HCPCS code for TOT

III+Wagner grade threshold

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

40 sessionscommon trial regimen

41.7%12-week closure (TWO2 active)

Coverage Criteria and Evidence Summary

inv-01: Primary Therapy Indications

Covered when ALL of the following are met

Primary Indications: Systemic hyperbaric oxygen therapy in single or multiplace chambers is considered medically necessary first-line treatment for acute carbon monoxide poisoning; air or gas embolism; decompression sickness; and exceptional blood loss when transfusion is not an option.

inv-02: Adjunctive Therapy Indications

Covered when ALL of the following are met

Adjunctive Indications: Systemic hyperbaric oxygen therapy in single or multiplace chambers is considered medically necessary adjunctive treatment for acute cyanide poisoning (after antidote administration); acute traumatic peripheral ischemia/insufficiency (e.g., crush injuries, compartment syndrome, suturing of severed limbs); avascular necrosis; central retinal artery occlusion; clostridial myositis/myonecrosis (gas gangrene); compromised skin grafts and flaps; delayed osteoradionecrosis (including pre- and post-dental extraction in an irradiated mandible); idiopathic sudden sensorineural hearing loss within four weeks of symptom onset; intracranial abscess; necrotizing soft tissue infections; osteomyelitis unresponsive to conventional interventions; radiation-induced cystitis/hemorrhagic cystitis; soft tissue radionecrosis; acute thermal burns requiring inpatient hospitalization; and Wagner grade III or higher diabetic lower extremity wounds that have failed standard wound therapy.ISSHL within 4 weeks; Wagner grade III+ after failure of standard therapy

Most diabetic wound protocols used ~2–2.5 ATA, 90–120 minutes, 20–40 sessions.

inv-03: Topical Oxygen Therapy—Diabetic Foot Ulcers

Covered when ALL of the following are met

TOT for Diabetic Foot Ulcer: Topical oxygen therapy is considered medically necessary as an adjunct treatment of a diabetic foot ulcer that has failed to heal with optimal standard of care.failed optimal standard of care

TOT devices have FDA 510(k) clearance for skin ulcerations including diabetic ulcers.

inv-04: Evidence summaries and implied coverage stance

Coverage stance and supporting evidence summaries by indication

Acute Coronary Syndrome / Acute MI: Systematic review (Bennett et al.) of RCTs (n=665) showed decreased risk of death and other cardiologic endpoints but authors cautioned results are limited by small trials and methodological shortcomings; routine application not justified.

CABG preconditioning: Single RCT (Yogaratnam et al., n=81) found some intra/postoperative hemodynamic benefits but study limitations and non-significant differences limit conclusions.

Acute or Chronic Cerebral Vascular Insufficiency: Insufficient evidence to support HBOT for cerebral vascular insufficiency.

Acute Thermal and Chemical Pulmonary Damage (non-CO poisoning): Evidence does not support HBOT for smoke inhalation or pulmonary insufficiency absent acute carbon monoxide poisoning.

inv-05: TOT for refractory diabetic foot ulcers (evidence-based)

Covered when ALL of the following are met (evidence context from trials and systematic reviews):

TOT for DFU coverage criteria: 1) Full‑thickness diabetic foot ulcer present ≥4 weeks and ≤1 year despite optimized standard of care; 2) Ulcer size ≥1 cm² and ≤20 cm² after debridement (per trial entry criteria); 3) No active severe infection, gangrene, osteomyelitis, active Charcot foot, uncontrolled diabetes (HgbA1c >12%), known malignancy, or end‑stage renal disease on dialysis; 4) Concurrent optimized SOC documented (debridement, offloading, infection management, vascular assessment, glucose control); 5) Therapy delivered per studied protocol (e.g., TWO2: ~90 minutes daily, five times/week up to 12 weeks) and monitored for adverse events.

Derived from RCT inclusion/exclusion criteria (Frykberg TWO2 trial) and systematic reviews/meta-analyses supporting TOT as adjunctive therapy.

inv-06: HBO — indications lacking sufficient evidence

Not covered / not established (evidence insufficient) for the following conditions:

HBO not established indications: HBO efficacy has not been established for vascular dementia, epilepsy, fractures (acute/delayed union/nonunion), cluster and migraine headaches, hepatic necrosis, HIV-related fatigue, in vitro fertilization adjunct, Lyme disease, lymphedema, malignant otitis externa, multiple sclerosis, mycoses (e.g., zygomycosis), nonvascular chronic brain syndromes (Alzheimer's, Pick's, Korsakoff's), ophthalmologic conditions other than central retinal artery occlusion, organ transplant/storage adjunct, penile glans necrosis, pulmonary emphysema, complex regional pain syndrome/reflex sympathetic dystrophy, rheumatoid arthritis, sepsis, sickle-cell disease, soft tissue injury, spinal cord injury, stroke (except air embolism), tetanus, tinnitus, venous stasis ulcers, and various other indications where evidence is limited to case reports/series.

List compiled from systematic reviews, RCTs, and FDA caution regarding off-label indications.

inv-07: Topical Oxygen Therapy — Medical Necessity

Covered when ALL of the following are met:

Topical Oxygen Therapy (TOT) coverage: TOT is considered medically necessary when used as an adjunct treatment of a diabetic foot ulcer that has failed to heal with optimal standard of care.failed to heal with optimal standard of care

HCPCS A4575 listed for topical hyperbaric oxygen chamber, disposable.

inv-08: Systemic Hyperbaric Oxygen — Medical Necessity

Covered when ALL of the following are met (per applicable policy statements):

Systemic Hyperbaric Oxygen Therapy: Considered medically necessary when criteria in the applicable systemic HBO policy statements are met (see policy sections for primary and adjunctive indications and specific clinical thresholds).

CPT 99183 and HCPCS G0277 cited for systemic HBO services.

inv-09: Topical oxygen therapy — coverage update

Summarized coverage changes from revision history

Topical oxygen therapy for diabetic foot ulcer: Changed from not covered to covered: topical oxygen therapy as adjunct treatment for a diabetic foot ulcer that has failed to heal with optimal standard of care.failed to heal with optimal standard of care

Focused Review date: 9/15/2025.

inv-10: Other indication coverage changes

Avascular necrosis: Changed from not covered to covered.

Annual review dated 5/15/2025.

Penile glans necrosis: Explicitly listed as not covered.

Added as not covered on 5/15/2025.

Systemic hyperbaric oxygen therapy in single or multiplace chambers is listed in this policy as not medically necessary for a broad set of conditions. Examples from the policy include actinomycosis; acute cerebral edema; acute coronary syndrome/myocardial infarction; chronic cerebral vascular insufficiency; acute wounds, flaps, and grafts; autism spectrum disorders; traumatic brain injury/closed head injury; cerebral palsy; COVID-19; cutaneous decubitus (pressure) ulcers; fractures (acute, delayed union, nonunion); malignant otitis externa; multiple sclerosis; organ transplantation; pulmonary emphysema; reflex sympathetic dystrophy/complex regional pain syndrome; rheumatoid arthritis; sepsis; sickle cell disease; spinal cord injury; stroke; tinnitus; venous stasis ulcers, and many other listed indications. Providers should assume HBO for these listed conditions will be treated as not medically necessary unless explicit coverage criteria elsewhere in the policy apply.

Topical oxygen therapy (TOT) is covered by this policy only as an adjunct treatment for a diabetic foot ulcer that has failed to heal with optimal standard of care. The policy explicitly states that TOT is not medically necessary for any other indication. The HCPCS code cited for topical hyperbaric oxygen chamber, disposable is A4575 when used in the covered adjunctive DFU context.

The policy summarizes systematic reviews and randomized trials concluding there is no convincing support for routine use of HBOT for acute wounds, flaps, and grafts due to small, heterogeneous, and low-quality studies. Similarly, for cerebral palsy the evidence from multiple RCTs and systematic reviews shows no improvement in motor, cognitive, or functional outcomes compared with controls; therefore HBOT is not supported for CP.

The FDA has issued consumer warnings that hyperbaric oxygen therapy has not been clinically proven to cure or be effective for acute COVID-19, and the policy notes the FDA also includes autism among conditions for which HBOT is not proven. The UHMS and FDA statements cited in the policy emphasize the need for well‑designed trials and careful documentation for any off‑protocol use.

Per an FDA communication cited in the policy, the safety and effectiveness of HBO have not been established for numerous off‑label conditions. The FDA list referenced includes conditions such as AIDS/HIV, Alzheimer’s disease, autism, asthma, Bell’s palsy, depression, diabetes (general), heart disease, hepatitis, migraine, multiple sclerosis, Parkinson’s disease, spinal cord injury, sports injury, and stroke.

The Undersea and Hyperbaric Medical Society (UHMS) position, as cited in the policy, states that topical oxygen is not equivalent to hyperbaric oxygen and that UHMS does not recommend topical hyperbaric oxygen outside of clinical trials. Consequently, outcomes from HBO studies cannot be directly applied to topical oxygen modalities.

Several reference‑only chunks in the policy provide literature citations and guideline material but do not themselves state explicit coverage exclusions or not‑medically‑necessary determinations. These reference listings are presented for context and evidence review rather than as standalone coverage decisions.

Among the many conditions listed as not medically necessary, the policy explicitly names penile glans necrosis as a not‑covered indication (added in the 2025 annual review). This specific exclusion appears in the policy’s list of noncovered conditions.

In summary, systemic hyperbaric oxygen therapy is designated not medically necessary for a large number of listed indications (see policy lists). Topical oxygen therapy (TOT) is considered medically necessary only as an adjunct for diabetic foot ulcers that have failed to heal with optimal standard of care; TOT is not medically necessary for other indications. The policy cites FDA and UHMS guidance to support these distinctions and to caution against extrapolating HBO evidence to topical oxygen therapies.

The policy emphasizes that routine use of HBOT is not medically necessary for a range of neurologic and developmental conditions including autism spectrum disorder, traumatic brain injury/post‑concussion syndrome, and cerebral palsy, because randomized trials and systematic reviews fail to show consistent benefit versus sham or standard care.

The policy lists multiple conditions for which the efficacy of HBO has not been established. Examples include vascular dementia, malignant otitis externa, acute ischemic stroke (except for air embolism), and venous stasis ulcers. The cited systematic reviews and Cochrane analyses conclude evidence is insufficient or inconsistent to support routine HBO use for these conditions.

UHMS guidance is explicitly cited to state that topical oxygen is not equivalent to hyperbaric oxygen. UHMS does not recommend topical hyperbaric oxygen (THBO/TOT) outside of clinical trials and warns that outcomes from systemic HBO studies should not be generalized to topical oxygen devices.

Several reference chunks in the policy list studies, systematic reviews, and guideline sources without making independent 'not medically necessary' determinations; these materials are included as evidence background and do not by themselves change coverage language.

The policy revision history documents that several previously not‑covered indications were revised during recent reviews. The focused review effective 9/15/2025 changed topical oxygen therapy from not covered to covered as an adjunct for diabetic foot ulcers that have failed optimal standard of care; other revision notes list coverage status changes but detailed rationale text appears elsewhere in the document.

Coding and Billing Codes

Systemic Hyperbaric Oxygen CPTCPTCovered

99183

Physician or other qualified health care professional attendance and supervision of hyperbaric oxygen therapy, per session

Systemic Hyperbaric Oxygen HCPCSHCPCSCovered

G0277

Hyperbaric oxygen under pressure, full body chamber, per 30 minute interval

Topical Oxygen Therapy HCPCSHCPCSCovered

A4575

Topical hyperbaric oxygen chamber, disposable

Wagner grade requirement — diabetic lower extremity wounds

Wagner grade requirementWagner grade III or higher for diabetic lower extremity wounds (deep ulcer with abscess/osteomyelitis [Grade III], gangrene of toes/forefoot [Grade IV], or gangrene of entire foot [Grade V])

Context from trialsRandomized trials supporting HBO for Wagner III–V used protocols commonly at 2–2.5 ATA for 90–120 minutes per session for 20–40 sessions

Clinical prerequisiteWounds must be refractory to aggressive medical management including wound care, glucose control, debridement or revascularization

SSHL timing — HBO as adjunct

Timing for SSHL (best evidence)HBO is best used as an adjunct within 2 weeks of symptom onset for idiopathic sudden sensorineural hearing loss (ISSHL)

Provider Actions, Prior Authorization & Documentation

Billing Rule

Coverage Determination & Billing — Coverage Policies guide interpretation of benefit plans

Coverage determinations require prior authorization when plan terms or benefit administration specify authorization; providers should submit documentation that aligns with the Coverage Policy criteria and with applicable benefit plan language. Claims submitted without covered diagnosis or procedure codes will be denied as not covered. Medical directors retain discretion to review requests individually considering plan terms, laws/regulations, relevant policies and the specific clinical facts.

Reimbursement only when services submitted under covered codes
Claims without covered codes will be denied as not covered

Prior Authorization

Prior authorization expectations

Background and Definitions

Systemic hyperbaric oxygen therapy involves the inhalation of 100% oxygen under increased atmospheric pressure (typically around 2–3 ATA) in a single‑ or multiplace chamber to increase tissue oxygenation. Sessions in clinical practice and trials have ranged from 30–120 minutes, commonly administered up to five times weekly; typical diabetic wound protocols reported in the literature used about 2–2.5 ATA for 90–120 minutes across 20–40 sessions.

Systemic Hyperbaric Oxygen (HBO/HBOT/HOT) — definition/parameters

DefinitionSystemic hyperbaric oxygen (HBO/HBOT/HOT): inhalation of 100% oxygen under increased atmospheric pressure (eg, 2–3 ATA) in a single- or multiplace chamber to increase tissue oxygenation

Typical session parametersSessions commonly last 30–120 minutes, up to five times per week; many diabetic wound protocols used 2–2.5 ATA for 90–120 minutes

Device/regulatory statusMono- and multiplace hyperbaric chambers are FDA Class II 510(k) devices

Topical Oxygen Therapy (TOT) — definition and device context

Policy Summary

PayerCigna

PolicyHyperbaric and Topical Oxygen Therapy

Policy CodePolicy 0053

Change TypeCoverage status updates (TOT & select indications)

Effective DateSep 15, 2025

Next Review DateMay 15, 2026

Key ActionDocument that a diabetic foot ulcer failed to heal with optimal standard of care before requesting topical oxygen therapy as adjunctive treatment.

SourceLink

On This Page

Acute Wounds, Flaps, and Grafts: Systematic review found heterogeneous, low-quality studies with conflicting outcomes; data do not support HBOT for these indications.

Autism Spectrum Disorder: Multiple trials and reviews produce inconsistent results; overall no convincing evidence that HBOT improves core ASD symptoms; UHMS/FDA note lack of proven benefit.

Traumatic Brain Injury / Concussion / Post-concussion Syndrome: Systematic reviews and RCTs report no consistent benefit versus sham; routine use not supported.

Brown Recluse Spider Bites: Case studies did not show HBOT added benefit over standard wound care and antibiotics.

Cancer / Radiotherapy adjunct: Cochrane review (n=2286) suggests some benefit for head and neck cancers but increased risk of severe local radiation reactions and oxygen-toxic seizures; overall evidence inconsistent and condition-specific.

Cerebral Palsy: Multiple RCTs and reviews show no improvement in motor/cognitive outcomes compared to controls; HBOT not supported for CP.

COVID-19 / Long COVID: Insufficient evidence for acute COVID-19; UHMS supports IRB-approved trials and documented off-protocol use; one RCT (n=73) showed medium effect-size improvements in selected cognitive and QoL domains but further study required.

Salvage windowPatients presenting after 2 weeks may still experience improvement; literature and UHMS note benefit within 4 weeks as salvage therapy in some cases

Standard therapy contextHBO is used as an adjunct for patients refractory to initial systemic and/or intratympanic corticosteroids

When prior authorization is required by the member’s plan or utilization management program, expect requests to include clinical documentation demonstrating the diagnosis, prior standard-of-care (SOC) therapies, timing and details of prior treatments, and rationale for the requested advanced oxygen therapy. Documentation should match regimens and trial parameters used in pivotal randomized controlled trials where applicable (for example, trials commonly used 20–40 sessions or 40 sessions at specified atmospheres and durations for systemic HBOT). Reviewers will expect clear demonstration that SOC was optimized and failed before adjunctive therapies are requested.

Include diagnosis and relevant dates
Detail prior SOC, number of sessions, and response
Cite prior trial regimens when applicable (e.g., 40 sessions at trial-specified ATA/duration)

Prior Authorization

Prior authorization expectation for TWO2/TOT

For TWO2/TOT home therapy (e.g., cyclical pressured TWO2 systems), prior authorization requests should document that the diabetic foot ulcer received at least four weeks of optimized SOC prior to initiation of TWO2/TOT, and should include inclusion/exclusion criteria consistent with published trials (e.g., ulcer size and duration, absence of uncontrolled infection/gangrene/osteomyelitis, HbA1c limits, renal function limits). Provide treatment regimen details (daily 90 minutes, frequency per week, total planned weeks/sessions) and concurrent SOC measures.

Document SOC ≥ 4 weeks prior to TWO2/TOT (per TWO2 trial design)
Provide ulcer characteristics: grade, size (post-debridement), duration
List exclusions present in trials (active severe infection, gangrene, osteomyelitis, uncontrolled diabetes, dialysis/creatinine limits)
Specify planned TWO2/TOT regimen (e.g., 90 min daily, 5x/week, up to 12 weeks)

Note

TOT prior authorization / coverage headline

For topical oxygen therapy (TOT) coded A4575 when used as an adjunct for diabetic foot ulcers that have failed optimal SOC, the policy lists A4575 as medically necessary; however, the policy text does not specify a uniform, separate prior authorization policy in these excerpted chunks. Providers should follow their specific plan’s prior authorization rules and submit required clinical documentation when authorization is required by the plan.

A4575 listed as medically necessary as adjunct for DFU
No separate PA process specified in these policy excerpts — follow payer/plan-specific PA rules

Note

Prior authorization — not specified in these chunks

Some policy excerpts do not state explicit prior authorization or step therapy requirements; when absent, providers must still follow the member’s benefit plan and any delegated vendor requirements. Lack of an explicit PA statement in the policy does not remove the need to check plan-level authorization rules.

No explicit prior authorization statement in certain reference chunks
Check member’s benefit plan for plan-specific PA or utilization management requirements

Documentation Required

No explicit documentation checklist provided in excerpt

No explicit documentation checklist is provided in these excerpts. Use the policy references and cited trials/guidelines to assemble supporting documentation for authorization: diagnosis, prior SOC details and dates, wound characteristics, prior outcomes, planned regimen, and exclusion criteria.

There is no single checklist provided in the policy excerpts
Assemble documentation based on trial inclusion/exclusion criteria and guideline recommendations

Denial Risk

No denial triggers are specified in these reference-only chunks

The policy and referenced sources do not list specific denial triggers in the excerpted blocks; however, denials may arise from plan exclusions, services billed with non-covered codes, or use of TOT/HBO for unsupported indications. Providers should anticipate denials when the requested service falls outside the covered indications, when required SOC trials are not documented, or when exclusions (e.g., newly added not-covered conditions) apply.

No explicit denial triggers listed in these reference-only chunks
Denials may occur if: service billed for unsupported indication; missing covered code; insufficient SOC trial documentation; policy exclusion applies (see revision notes)

Documentation Required

Documentation implications of coverage changes

Coverage changes in the policy (for example, topical oxygen therapy changed from not covered to covered as adjunct for DFU) have documentation implications: providers should update authorization requests and medical records to reflect new coverage criteria, ensure documentation demonstrates prior SOC failure and alignment with trial/guideline inclusion criteria, and be aware that newly listed exclusions (e.g., certain necrosis indications) may create denial risk if applied.

Update prior authorization templates and clinical notes to match revised coverage criteria (e.g., TOT now covered as adjunct for DFU)
Ensure documentation demonstrates failure of optimal SOC and matches trial inclusion/exclusion where applicable
Be aware of newly added not-covered indications (see policy revision notes)

Documentation Required

Trial documentation examples

Trial documentation examples that support what reviewers will expect include: TWO2 randomized trial parameters (SOC ≥4 weeks, ulcer size and duration limits, exclusion list, home-administered 90 min daily treatments up to 12 weeks, primary endpoint at 12 weeks and follow-up at 12 months) and systemic HBOT trial regimens (daily exposures at 2–2.5 ATA for 90–120 minutes for a total of 20–40 sessions in many diabetic foot ulcer studies). Include outcome measures and follow-up when available.

Two2 trial: SOC ≥4 weeks, ulcer ≥1 cm² and ≤20 cm² post-debridement, daily 90 min x 5/wk up to 12 weeks; primary endpoint at 12 weeks
HBOT DFU trials: commonly 20–40 sessions at 2–2.5 ATA for 90–120 minutes

Documentation Required

Required clinical documentation for TWO2/TOT

Required clinical documentation for TWO2/TOT prior authorization should include: detailed wound assessment (Wagner grade, size post-debridement, duration), documentation of optimized SOC and duration (≥4 weeks for TWO2 per trial), specific exclusions (active severe infection, gangrene, osteomyelitis, HbA1c or renal thresholds used in trials), planned device/regimen parameters, and records of concurrent SOC measures (debridement, offloading, infection management, glycemic control).

Wound details: Wagner grade, post-debridement size, duration
Evidence of optimized SOC and duration (e.g., ≥4 weeks for TWO2)
Trial-based exclusions: no active severe infection/gangrene/osteomyelitis, controlled diabetes thresholds, renal function limits
Planned TOT/TWO2 regimen (session length, frequency, total duration)
Concurrent SOC interventions (debridement, offloading, vascular assessment, infection control, glucose management)

Note

References include guideline/position sources that may inform documentation expectations

Guidelines and position statements (ADA 2025 Standards of Care, IWGDF 2023, UHMS statements, and systematic reviews) inform when TOT or HBOT should be considered and what documentation to supply. These references support TOT as an adjunct when optimal SOC alone has failed and provide trial- and practice-based expectations for prior SOC and patient selection.

ADA 2025: consider randomized controlled trial–proven adjunctive agents including TOT for chronic DFU failing optimal SOC
IWGDF 2023: conditional recommendation to consider topical oxygen as adjunct when SOC failed
UHMS and other position statements inform trial design and off-protocol considerations

Step Therapy

Stepwise Use for Diabetic Foot Ulcers

Stepwise use: For Wagner grade III–V diabetic foot ulcers, systemic HBOT is supported as an adjunctive therapy after failure of aggressive medical management including optimized wound care and revascularization when indicated; TWO2/TOT evidence supports use as an adjunct after failure of optimal SOC (documented trial of SOC).

HBOT: adjunct for Wagner grade III–V DFU refractory to aggressive management
TOT/TWO2: adjunct after failure of optimized SOC (per trials and guideline recommendations)

Step Therapy

Step therapy for neurologic indications

Step therapy for neurologic indications: randomized trials have not demonstrated routine benefit of HBO for traumatic brain injury/post-concussion; when HBO is considered for neurologic conditions, expect documentation of prior SOC therapies and justification referencing the evidence (many trials used 40-session regimens and sham-controlled designs).

TBI/post-concussion: RCTs did not show routine benefit — document prior SOC and rationale if requesting HBO
Provide prior therapy details and reference relevant trial designs when applicable

Step Therapy

Step requirement: trial of SOC

Step requirement — trial of SOC: The evidence and guideline context consistently require an adequate trial of optimized SOC before adjunctive TOT or HBOT for DFU will be considered medically necessary. For TWO2 specifically, the pivotal trial required at least four weeks of SOC prior to randomization.

Document optimized SOC and duration (≥4 weeks for TWO2 per trial protocol)
Include details of debridement, offloading, dressings, infection and glycemic control

Note

Guidelines recommend considering TOT as adjunct when optimal SOC alone has failed

Guidelines recommend considering TOT as one of several randomized-controlled trial–proven adjunctive options when optimal SOC alone has failed; selection should be individualized based on wound characteristics, patient factors, and resource availability.

TOT is among several adjunctive options recommended when SOC fails (ADA, IWGDF)
Consider patient values, wound features, and available resources when selecting adjunctive therapy

Step Therapy

No step therapy rules are contained in these reference listings

No step therapy rules are contained in these reference listings; where step therapy is required it will be specified by the member’s benefit plan or utilization management program. Providers should verify plan-level step requirements before submitting requests.

Policy excerpts do not impose plan-level step therapy rules in these chunks
Follow member’s benefit plan or UM program for any step therapy requirements

Step Therapy

Step therapy

Step therapy: when present at the plan level, expect requirements to show failure of specified prior therapies (e.g., optimized SOC) before authorization of adjunctive oxygen therapies; absent plan-level step therapy, demonstrate medical necessity through documentation of SOC failure and trial-aligned patient selection.

If plan imposes step therapy, submit evidence of failure of required prior therapy(ies)
If no plan step therapy, use trial/guideline-based documentation to demonstrate medical necessity

DefinitionTopical Oxygen Therapy (TOT): direct application of oxygen to a localized wound site at slightly above atmospheric pressure via FDA-cleared devices

Device examplesFDA-cleared devices include Hyper-Box (HyperBox/HyperBox Topical Wound Oxygen System), O2 Boot™, Natrox, and EPIFLO-28

Indications in device 510(k) summariesThese devices are indicated for skin ulcerations including diabetic foot ulcers, venous stasis ulcers, post-surgical infections, decubitus ulcers, grafts, burns and frostbite

Major Adverse Coronary Events (MACE) — definition used in ACS trials

MACE definition (trial context)Major adverse coronary events (MACE) as referenced in ACS trials include death, reinfarction, dysrhythmias and other major cardiac events

Evidence summaryCochrane/systematic reviews (eg, Bennett et al.) reported reductions in death, re-infarction, dysrhythmias and MACE but cautioned interpretation due to small trials and methodological shortcomings

Implication for routine useDespite favorable signals, routine application of HBO for ACS is not justified without larger, rigorous trials

Post-COVID (long-COVID) — definition used in HBOT trials

Definition used in HBOT trialsPost-COVID (long‑COVID) defined as persistent symptoms for at least three months after confirmed SARS‑CoV‑2 infection

Trial exampleZilberman‑Itskovich et al. randomized patients with symptoms ≥3 months to 40 daily HBO sessions vs sham (n=73) with cognitive and QoL outcomes

Evidence stanceAvailable trials are limited; literature concludes insufficient evidence for routine HBOT in acute or long COVID and supports further well-designed trials

Topical Oxygen Therapy (TOT) — delivery methods and application notes

Delivery methodsTWO2 (HyperBox) is a multimodality cyclical pressure topical wound oxygen home system delivering therapy at home; other TOT devices provide continuous or intermittent topical oxygen via boot, sleeve, wearable generator, or disposable concentrator

Typical application regimen (TWO2)In the TWO2 RCT, patients self‑administered therapy at home for 90 minutes daily, five times per week, up to 12 weeks

Indication contextStudied as adjunctive home therapy for refractory DFUs after ≥4 weeks of optimized standard of care

TWO2 therapy (HyperBox) — definition and trial parameters

Definition and protocol (TWO2/HyperBox)TWO2 (HyperBox) is a cyclical pressured topical wound oxygen home care system evaluated in a double‑blind RCT for refractory DFUs; in the trial patients used 90 minutes daily, five times per week, up to 12 weeks

Home therapy modalityTWO2 therapy is delivered by a device that provides cyclical pressure and topical oxygen suitable for self‑administration at home

Trial population/contextUsed in patients with full‑thickness DFUs 1–20 cm² present 4 weeks–1 year who failed at least 4 weeks of SOC; primary endpoint was 12‑week healing

Topical oxygen therapy (TOT) — mechanism and therapeutic intent

MechanismTopical oxygen diffuses oxygen into the ulcer wound bed to eliminate local hypoxia and stimulate growth factors that contribute to angiogenesis and wound healing

Therapeutic intentUsed to directly augment oxygen tension at wound surface to improve healing as an adjunct to standard wound care

Supporting guideline statementWound Healing Society (2023) states TOT increases incidence of healing and decreases time to heal (Level I rationale) by delivering oxygen to the wound bed

UHMS references — position statements cited

UHMS position/reference sourcesUHMS position statements and indications (eg, Indications for HBO, 15th ed., and position statements on COVID‑19 and ISSHL) are cited as authoritative references for accepted and non‑accepted HBO indications

Specific UHMS guidanceUHMS supports HBOT for ISSHL when patients present within 14 days and notes best evidence supports use within two weeks of symptom onset

Role in policyUHMS indications are used to define recognized primary and adjunctive HBO indications in this coverage policy

FDA 510(k) device summaries — device clearance context

FDA 510(k) contextMultiple topical wound oxygen systems and mono/multiplace hyperbaric chambers have 510(k) clearance (eg, HyperBox K080966; O2Boot K971507; Makai and OxyHeal chamber summaries), cited as device clearance context

Device indications in 510(k)510(k) summaries list indications including treatment of skin ulcerations such as diabetic foot ulcers and other ulcer types for these devices

Implication for coverage/codingFDA 510(k) status supports identification of specific device HCPCS/CPT codes referenced elsewhere in the policy

Topical oxygen therapy / Hyperbaric oxygen therapy — short definitional contrast

Systemic vs topical — core distinctionSystemic HBO delivers 100% oxygen inhaled under increased atmospheric pressure (eg, 2–3 ATA) to the whole body, whereas TOT applies oxygen directly to a localized wound at slightly above atmospheric pressure

Typical settings and devicesSystemic HBO uses mono‑ or multiplace chambers (FDA Class II 510(k)); TOT uses various specialized devices (boots, sleeves, wearable generators, disposable concentrators) with 510(k) clearance

Clinical intentSystemic HBO is used for systemic/adjunctive indications (eg, CO poisoning, gas embolism, select problem wounds); TOT is intended as a localized adjunct for wound healing (eg, diabetic foot ulcers) per trial evidence