Prosthetic Lower Microprocessor denied as duplicate or overlapping therapy by Aetna?

Aetna's specific coverage criteria for prosthetic lower microprocessor 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 a Microprocessor-Controlled Lower-Limb Prosthesis as "Duplicate Therapy"

A "duplicate therapy" denial on a lower-limb prosthesis — typically a microprocessor-controlled knee or ankle device — means Aetna's system identified an existing prosthesis already on file for the same limb and concluded that supplying a second device constitutes unnecessary duplication. This denial often fires when a replacement prosthesis is requested before the end of Aetna's anticipated useful-life period, or when two separate component claims (e.g., socket and microprocessor unit) were processed in a way that looked like two complete prostheses.

This denial is frequently a claims-coding problem rather than a substantive clinical disagreement, and it is well worth appealing.

## Your Federal Appeal Rights

Under ACA §2719 and ERISA §503:

• You are entitled to the specific basis for the duplicate-therapy determination, including the date and code of the prior device Aetna has on file.
• If your prior device has reached the end of its functional life, was damaged, or no longer meets your functional needs due to a documented clinical change, that is a complete defense to a duplicate-therapy denial.
• External review is available after exhausting internal appeals; the window is typically around four months from the final denial — confirm the exact deadline in your denial letter.
• Expedited review is available when a standard timeline would seriously jeopardize your mobility, safety, or health.

## The Appeal Process

1. Request the EOB or claims record that Aetna believes represents the prior duplicate device — confirm the date, HCPCS code, and limb laterality. 2. If the prior device is a different component, a different limb, or a different time period, document that clearly in your appeal. 3. If the prior device was legitimately provided but is now inadequate (wear, damage, functional change), obtain clinical documentation from your prosthetist and treating physician. 4. Submit the internal appeal with a prosthetist's written assessment and the prescribing physician's letter. 5. If the internal appeal fails, file for independent external review.

## Documentation to Gather

• Prior device records: Date of prior fitting, HCPCS code, and current functional status assessment from your prosthetist.
• Clinical need documentation: Physician and prosthetist notes explaining why a new or replacement device is medically necessary now.
• Functional assessment: Standardized mobility or functional classification documentation from your treating team (your prosthetist will know the relevant classification system).
• Damage or wear evidence: Prosthetist's written finding on component condition, if replacement is sought due to end of useful life.
• Aetna's coverage policy: Current published version for lower-limb prostheses — available on Aetna's provider portal.

## Criteria-Mapping Structure

Side-by-side table: left column = Aetna's basis for duplicate finding (prior device date/code); right column = why this request is not duplicative (different component, different period, documented functional change). Each cell should be one sentence backed by a specific document. This format gives the reviewer a factual record to overturn the denial without requiring them to interpret narrative.