Appeal — TEST-CLAIM-00024

Date: [Date of Submission]

Via: [Submission Method]

Synthetic Aetna
Appeals & Grievances Department
[Payer Address]

Re: Formal Appeal of Claim Denial
Claim Number: TEST-CLAIM-00024
Internal Claim ID: 7171b2e1-59d6-4d7d-a4f0-31e7732c80ff
Date of Service: January 11, 2026
Denial Date: March 18, 2026
Denied Amount: $628.15
Procedure Codes: CPT 61049, CPT 86556
Diagnosis Code: F32.48

Dear Synthetic Aetna Appeals Department,

This letter constitutes a formal first-level appeal on behalf of our facility regarding the denial of Claim TEST-CLAIM-00024, adjudicated by Synthetic Aetna on March 18, 2026. The claim was denied under reason code CO-252, indicating that an attachment or other documentation was required to adjudicate the claim. We respectfully contest this denial and request that the claim be reprocessed and paid in full for the denied amount of $628.15.

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I. BACKGROUND AND BASIS FOR DENIAL

The claim in question pertains to services rendered on January 11, 2026, and includes the following procedure codes billed in connection with the patient's primary diagnosis of Major Depressive Disorder, Single Episode, Unspecified Severity (ICD-10: F32.48):

  - CPT 61049: Neurosurgical procedure
  - CPT 86556: Immunology/serology test

The payer issued a denial under CO-252, citing the absence of required attachments or supporting documentation necessary to adjudicate the claim. The total billed amount for the claim is $1,828.21, of which $628.15 was denied pending receipt of the identified documentation.

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II. GROUNDS FOR APPEAL

We respectfully submit that this denial represents a procedural deficiency that is directly curable upon submission of the documentation identified below. The CO-252 denial code does not constitute a determination of non-coverage or lack of medical necessity; rather, it is an administrative request for supplemental documentation. The services rendered were medically necessary, clinically appropriate, and are supported by contemporaneous documentation that exists in the patient's medical record. The denial is therefore not a reflection of any substantive coverage dispute, and the claim remains fully adjudicable.

In accordance with Synthetic Aetna's documentation and attachment requirements, and consistent with the payer's own policy basis for CO-252 denials, the claim should be reprocessed upon receipt of the enclosed supporting documentation.

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III. SUPPORTING DOCUMENTATION ENCLOSED

In support of this appeal, the following documents are enclosed with this letter:

  1. Operative report or procedure documentation for CPT 61049, confirming the performance and clinical scope of the neurosurgical procedure on January 11, 2026.

  2. Laboratory report or test results for CPT 86556, confirming the performance and clinical findings of the immunology/serology test on January 11, 2026.

  3. Clinical notes supporting the medical necessity of both procedures, including the treating physician's assessment and plan of care.

  4. The enclosed letter of medical necessity from the treating physician, which documents the clinical rationale connecting CPT 61049 and CPT 86556 to the patient's primary diagnosis of Major Depressive Disorder, Single Episode, Unspecified Severity (ICD-10: F32.48).

  5. Imaging reports, if applicable to the neurosurgical procedure, as part of the complete medical record.

  6. Pathology report, if applicable, as part of the complete medical record.

These documents collectively establish that both procedures were performed as billed, were clinically indicated, and are appropriately linked to the documented diagnosis. The documentation package provided herein directly satisfies the attachment requirements cited under CO-252 and addresses all documentation deficiencies identified in the denial.

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IV. POLICY ANALYSIS

Under Synthetic Aetna's applicable documentation and attachment requirement policy, a CO-252 denial is a request for additional documentation and does not represent a final adverse benefit determination on the merits of coverage or medical necessity. Because the required documentation exists in the patient's medical record and is being provided with this appeal, the procedural basis for the denial has been fully remediated. There is no substantive coverage or medical necessity dispute at issue; the claim is adjudicable upon review of the enclosed materials.

We respectfully assert that, consistent with this policy framework, the payer is obligated to reprocess the claim upon receipt of the enclosed documentation and to issue payment for the denied amount.

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V. REQUESTED REMEDY

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

  1. Accept and review the enclosed documentation in satisfaction of the CO-252 attachment requirement;
  2. Reprocess Claim TEST-CLAIM-00024 in its entirety; and
  3. Issue payment of the denied amount of $628.15 in accordance with the applicable contractual and coverage terms.

Please note that the appeal deadline for this claim is September 14, 2026. We respectfully request a timely determination in accordance with applicable state and federal prompt-pay requirements and the terms of our provider agreement.

Should you require any additional information or clarification, please contact our Denials Management Department at the contact information below. We appreciate your prompt attention to this matter and look forward to a favorable resolution.

Respectfully submitted,

[Authorized Signature]
[Name and Title]
[Hospital/Facility Name]
[Address]
[Phone Number]
[Fax Number]
[Date]

Enclosures:
  - Operative report / procedure documentation (CPT 61049)
  - Laboratory report / test results (CPT 86556)
  - Clinical notes supporting medical necessity
  - Letter of medical necessity (physician statement)
  - Imaging reports (if applicable)
  - Pathology report (if applicable)
  - Copy of original claim (TEST-CLAIM-00024)
  - Copy of denial explanation of benefits dated March 18, 2026