Appeal — TEST-CLAIM-00010

Date: [Date of Submission]

Synthetic Aetna
Appeals and Grievances Department
[Payer Address]

RE: Formal Appeal of Claim Denial
External Claim ID: TEST-CLAIM-00010
Internal Claim ID: 371f4d93-bb1a-4d06-9991-db253daa34e2
Payer: Synthetic Aetna
Date of Service: November 28, 2025
Denial Date: February 4, 2026
Denial Reason: CO-27 – Expenses Incurred After Coverage Terminated
Procedure Code(s): CPT 67912
Diagnosis Code(s): G43.01, E11.09
Billed Amount: $2,217.95
Denied Amount: $2,186.59
Appeal Deadline: August 3, 2026

Dear Synthetic Aetna Appeals and Grievances Department,

On behalf of the undersigned facility, we are submitting this formal first-level appeal in response to the denial of Claim TEST-CLAIM-00010, issued on February 4, 2026. Synthetic Aetna denied this claim under adjustment reason code CO-27, asserting that the expenses were incurred after the member's coverage had terminated. We respectfully contest this determination and request that the claim be reprocessed and paid in full.

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I. GROUNDS FOR APPEAL

The CO-27 denial is factually incorrect. The services at issue — CPT code 67912 (eyelid surgery) — were rendered on November 28, 2025. The enclosed member eligibility verification report, obtained as of the date of service, confirms that the member's coverage under Synthetic Aetna was active on November 28, 2025. The denial rationale — that coverage had already terminated prior to the service date — is directly contradicted by the official eligibility documentation.

Under Synthetic Aetna's own policies governing eligibility verification and coverage termination date determination, a CO-27 denial is appropriate only when services are demonstrably rendered outside an active coverage period. Where contemporaneous eligibility records establish that a plan was in force on the date of service, the factual predicate for a CO-27 denial does not exist, and the denial is subject to reversal upon presentation of those records.

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II. SUPPORTING DOCUMENTATION

The following documents are enclosed with this appeal and are submitted in support of the facility's position:

1. Member Eligibility Verification Report — An official eligibility verification report confirming the member's active coverage status as of November 28, 2025, the date of service.

2. Insurance Policy / Member ID Card — Documentation reflecting the member's plan enrollment and confirming coverage was in force on the date of service.

3. Explanation of Benefits or Coverage Termination Notice — A copy of any EOB or termination notice issued by Synthetic Aetna, obtained to identify the termination date asserted by the payer and to demonstrate it postdates or does not apply to the November 28, 2025 service date.

4. Hospital Records — Facility records documenting the date of service, procedure performed, and the clinical encounter on November 28, 2025.

5. Written Communication from Payer Regarding Coverage Status — Any correspondence from Synthetic Aetna pertaining to the member's coverage status, further substantiating that no valid termination had occurred as of the service date.

Taken together, these documents establish a clear and consistent record that the member's coverage was active when services were rendered, and that the CO-27 denial lacks a factual basis.

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III. REQUESTED REMEDY

We respectfully request that Synthetic Aetna:

1. Overturn the CO-27 denial of Claim TEST-CLAIM-00010 in its entirety;
2. Reprocess the claim in accordance with the member's active benefits as of November 28, 2025; and
3. Issue payment of the denied amount of $2,186.59 to the facility.

This appeal is being submitted within the applicable appeal deadline of August 3, 2026. Should additional information be required to resolve this matter, please contact the facility's billing and appeals department at the contact information provided below.

We appreciate Synthetic Aetna's prompt attention to this matter and trust that a thorough review of the enclosed eligibility documentation will confirm that the CO-27 denial should be reversed.

Respectfully submitted,

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

Enclosures:
- Member Eligibility Verification Report (as of 2025-11-28)
- Insurance Policy / Member ID Card
- Explanation of Benefits or Coverage Termination Notice
- Hospital Records (Service Date: 2025-11-28)
- Written Communication from Payer Regarding Coverage Status