Hyperbaric Oxygen denied as non-formulary by Aetna?

Aetna's specific coverage criteria for hyperbaric oxygen are defined in its own published medical/coverage policy and the FDA-approved prescribing label. A successful appeal documents that your medical records satisfy each criterion those sources list — confirmed diagnosis, any required prior treatments (with dates and outcomes), and clinical severity. If the exact criteria weren't included with your denial, request them in writing; your appeal then maps each requirement to the matching fact in your chart.

## Why Aetna Denied Hyperbaric Oxygen as "Non-Formulary" — and How to Appeal

A non-formulary denial for hyperbaric oxygen therapy (HBOT) is somewhat unusual since HBOT is a procedure rather than a drug. When Aetna uses this language for HBOT, it typically means that the specific type or setting of the service — for example, monoplace vs. multiplace chambers, or outpatient vs. hospital-based delivery — is not the preferred covered configuration under your specific plan, or that HBOT simply does not appear on your plan's covered services schedule. It can also arise when the procedure code submitted does not match the covered code in Aetna's system.

This denial is worth appealing because HBOT for FDA-cleared indications is an established, non-investigational treatment, and many plans that initially deny on non-formulary grounds will cover it through a medical necessity or exceptions process.

## Your Federal Appeal Rights

• Internal appeal: ERISA §503 and ACA §2719 entitle you to a full-and-fair internal review. File within the timeframe on your denial letter (typically 180 days).
• External review: After exhausting internal appeals, ACA §2719 provides access to an Independent Review Organization (IRO). You generally have four months (180 days) from the final adverse determination.
• Non-covered vs. excluded: Verify whether HBOT is a plan exclusion (harder to appeal) vs. simply not listed as a preferred benefit (more appealable via medical necessity exception). Request the Summary Plan Description (SPD) or Evidence of Coverage (EOC) to determine which applies.
• Expedited review: Available for urgent clinical situations; Aetna must respond within 72 hours.

## Documentation to Gather

1. Plan documents — request your Summary Plan Description or Evidence of Coverage to confirm whether HBOT is explicitly excluded or merely unclassified, and what the covered service schedule includes. 2. Procedure code review — ask your provider to verify that the correct CPT code(s) for HBOT were submitted and match what Aetna's system lists as covered. 3. FDA clearance for your indication — attach documentation showing HBOT is FDA-cleared for your specific diagnosis, establishing that it is an accepted, non-experimental treatment. 4. Prescriber medical-necessity letter — a letter explaining why HBOT is necessary for your condition and why the specific delivery setting used is clinically appropriate. 5. Diagnosis and clinical documentation — chart notes confirming diagnosis and severity, supporting the argument that HBOT is medically indicated regardless of formulary status.

## Criteria-Mapping Structure

For this denial type, your appeal should have two tracks: (1) an administrative track — confirming that the procedure code and setting were submitted correctly, and (2) a medical necessity exception track — demonstrating that even if HBOT requires special authorization, the clinical evidence fully supports coverage. Address both in your appeal letter to maximize chances of resolution.