Appeal — TEST-CLAIM-00061

Date: [Letter Date]

Via: [Submission Method]

Synthetic Aetna
Appeals and Grievances Department
[Payer Address]

Re: Formal Appeal of Claim Denial
External Claim ID: TEST-CLAIM-00061
Internal Claim Reference: 5f0836c6-3e3b-4594-8692-749ba824dee3
Payer: Synthetic Aetna
Date of Service: October 6, 2025
Denial Date: December 27, 2025
Diagnosis Code: S82.83 (Other Fracture of Lower Leg)
Procedure Codes: CPT 80804, CPT 64935, CPT 86983
Denied Amount: $819.08
Appeal Deadline: June 25, 2026

Dear Synthetic Aetna Appeals and Grievances Department,

This letter constitutes a formal first-level appeal on behalf of our facility regarding the denial of Claim TEST-CLAIM-00061. Synthetic Aetna issued a denial on December 27, 2025, applying adjustment reason code CO-55, classifying the above-referenced procedures as experimental or investigational. We respectfully contest this determination and request that the claim be reprocessed and payment issued for the denied amount of $819.08.

---

I. BACKGROUND AND BASIS FOR DENIAL

On October 6, 2025, the patient presented with a documented diagnosis of S82.83 (Other Fracture of Lower Leg). In the course of medically necessary evaluation and treatment, the following services were rendered and billed:

  - CPT 80804 – Chemistry Panel (Laboratory)
  - CPT 64935 – Nerve Block
  - CPT 86983 – Immunoassay/Other Laboratory Testing

Synthetic Aetna denied $819.08 of the $1,064.65 billed, citing CO-55: Procedure/treatment is deemed experimental/investigational by the payer. We submit that this designation is factually and clinically unsupported and that the denial should be overturned in full.

---

II. GROUNDS FOR APPEAL

A. The Denied Procedures Are Established, Non-Experimental Standards of Care

Peripheral nerve blocks (CPT 64935) are widely recognized, extensively studied, and routinely employed in fracture management and post-operative or acute pain control. Regional anesthesia and nerve block techniques are endorsed by mainstream clinical guidelines, including those published by the American Society of Regional Anesthesia and Pain Medicine (ASRA) and other authoritative bodies, as standard-of-care interventions for orthopedic and fracture-related pain. These are decidedly not experimental or investigational procedures.

Similarly, standard chemistry panels (CPT 80804) and immunoassay laboratory tests (CPT 86983) are routine, well-established diagnostic tools used in the clinical assessment and perioperative management of fracture patients. These procedures have FDA-recognized, commercially available platforms and are performed in accredited laboratories across the country as ordinary clinical practice. There is no credible clinical or regulatory basis for classifying these laboratory services as experimental or investigational.

B. The CO-55 Designation Is Inconsistent with the Patient's Documented Diagnosis and Clinical Need

The patient's diagnosis of S82.83 (Other Fracture of Lower Leg) provides clear clinical context for each of the billed services. Pain management via nerve block is directly indicated for fracture-related acute pain, and laboratory panels are standard components of the pre-operative and peri-operative workup. The treating physician's clinical judgment, as detailed in the enclosed letter of medical necessity, directly supports the appropriateness of these interventions for this patient's documented condition.

C. Payer's Own Coverage Policy Should Recognize These Services as Covered

Synthetic Aetna's experimental/investigational exclusion is intended to apply to procedures that lack sufficient clinical evidence or regulatory acceptance — not to procedures that are routinely covered and reimbursed throughout the industry. We respectfully submit that the application of CO-55 to CPT 64935, CPT 80804, and CPT 86983 in the context of a lower-leg fracture represents an erroneous application of this exclusion. To the extent Synthetic Aetna maintains coverage policy documents addressing these CPT codes, we request that the reviewer consult those policies, as we believe they will confirm coverage for these services.

D. Supporting Documentation Substantiates Medical Necessity and Established Status

The following documents are enclosed in support of this appeal:

  1. Letter of Medical Necessity – The treating physician's letter explains the clinical rationale for each billed procedure in the context of the patient's lower-leg fracture and documents why these services were necessary and appropriate.

  2. Peer-Reviewed Clinical Guidelines and Published Evidence – Enclosed clinical literature and/or guideline excerpts demonstrate that CPT 64935 (nerve block), CPT 80804 (chemistry panel), and CPT 86983 (immunoassay laboratory testing) are established, non-experimental interventions supported by mainstream clinical evidence.

  3. Published Clinical Evidence and/or FDA Guidance – Documentation confirming that the procedures at issue do not meet the definition of experimental or investigational as applied under standard insurance coverage criteria.

  4. Medical Records – Relevant portions of the patient's medical record documenting the diagnosis of S82.83, the clinical presentation, and the medical decision-making supporting each billed service.

  5. Payer Coverage Policy Documentation (if applicable) – Any Synthetic Aetna coverage policy language confirming that the billed CPT codes are recognized covered services under the patient's plan.

---

III. REQUESTED REMEDY

Based on the foregoing, we respectfully request that Synthetic Aetna:

  1. Overturn the CO-55 experimental/investigational denial in its entirety;
  2. Reprocess Claim TEST-CLAIM-00061 under the correct medical necessity criteria; and
  3. Issue payment of the denied amount of $819.08 in accordance with the patient's plan benefits and the contractual terms applicable to these covered services.

If the reviewer requires any additional clinical documentation or clarification, please contact our Appeals Department at [Facility Contact Information]. We are committed to providing any further information necessary to support prompt resolution of this matter.

Thank you for your prompt attention to this appeal. We trust that upon review of the enclosed documentation, Synthetic Aetna will agree that the CO-55 denial was applied in error and that payment of the outstanding balance is appropriate.

Respectfully submitted,

[Authorized Facility Representative Name]
[Title]
[Facility Name]
[Facility Address]
[Phone / Fax]
[Date]

Enclosures:
  - Letter of Medical Necessity (Treating Physician)
  - Peer-Reviewed Clinical Guidelines Supporting CPT 64935, 80804, and 86983
  - Published Clinical Evidence / FDA Guidance Regarding Non-Experimental Status
  - Relevant Medical Records (Diagnosis S82.83 and Clinical Presentation)
  - Payer Coverage Policy Documentation (if applicable)