Appeal — TEST-CLAIM-00023

Date: [Date of Submission]

Via: [Submission Method]

Synthetic Cigna
Appeals and Grievances Department
[Payer Address]

Re: Formal Appeal of Claim Denial
Claim Number: TEST-CLAIM-00023
Payer: Synthetic Cigna
Service Date: 2026-02-21
Denied Amount: $2,453.79
Denial Reason: CO-45 — Charges Exceed Contracted/Legislated Fee Arrangement
Appeal Deadline: 2026-07-14

Dear Synthetic Cigna Appeals Department,

On behalf of [Provider/Facility Name], we are submitting this formal first-level appeal contesting the denial issued on 2026-03-16 for claim number TEST-CLAIM-00023, covering services rendered on 2026-02-21. Synthetic Cigna applied denial code CO-45, asserting that the billed charges exceed the contracted or legislated fee arrangement, resulting in a denied amount of $2,453.79 against a total billed amount of $4,585.73. We respectfully submit that this denial is erroneous and request that the claim be reprocessed and the denied balance of $2,453.79 be paid in accordance with the applicable contracted fee schedule.

I. BACKGROUND AND BASIS FOR APPEAL

The claim at issue involves services provided on 2026-02-21 for a patient presenting with a diagnosis of fracture of other parts of lower leg (ICD-10: S82.88). The procedures billed include CPT codes 20561, 28136, and 29769. Synthetic Cigna processed the claim and reduced payment by $2,453.79, citing CO-45 and asserting that the billed charges exceed the contracted fee arrangement between the parties.

Our facility contests this determination. The contracted fee schedule and signed provider service agreement on file establish specific allowable rates for the procedure codes in question. Upon review of the payer's applied allowance against the rates documented in our executed agreement, we believe the payer's fee allowance calculation is incorrect and does not accurately reflect the negotiated contracted rates for CPT codes 20561, 28136, and 29769.

II. GROUNDS FOR OVERTURN

A CO-45 denial is appropriate only where billed charges genuinely exceed the contracted or legislated fee arrangement. However, such a determination is only valid if the payer has correctly identified and applied the rates set forth in the governing provider service agreement and its associated fee schedule. In this instance, there is a material discrepancy between the contracted rates as documented in our signed agreement and the allowance amounts applied by Synthetic Cigna in adjudicating this claim.

Specifically, we assert the following:

1. The signed provider service agreement between [Provider/Facility Name] and Synthetic Cigna establishes defined reimbursement rates for the procedure codes at issue. The payer's applied allowance for CPT codes 20561, 28136, and/or 29769 does not appear to reflect those negotiated rates, resulting in an underpayment of $2,453.79.

2. The fee schedule or rate table incorporated by reference into the executed contract supports a higher allowable amount than what Synthetic Cigna applied when adjudicating this claim. Any variance between the payer's applied rate and the rates documented in the executed contract constitutes an improper fee determination and is grounds for reversal of the CO-45 denial.

3. To the extent Synthetic Cigna applied a rate table or fee schedule other than the one governing this provider agreement, such application is inconsistent with the contractual obligations between the parties and should be corrected upon review of the enclosed supporting documentation.

4. No contract amendment or rate update has been identified that would authorize a reduction to the allowable amounts reflected in the original executed agreement for the dates of service in question.

III. SUPPORTING DOCUMENTATION

In support of this appeal, we enclose the following documents for Synthetic Cigna's review:

- The enclosed signed provider service agreement or contract between [Provider/Facility Name] and Synthetic Cigna, identifying the governing contractual relationship and applicable reimbursement terms.
- The enclosed fee schedule or rate table referenced in and incorporated into the contract, demonstrating the contracted rates applicable to CPT codes 20561, 28136, and 29769 as of the service date of 2026-02-21.
- The enclosed itemized bill, providing a detailed mapping of each CPT code to its corresponding billed charge, confirming that charges were submitted in accordance with the contractual fee arrangement.
- The enclosed documentation of any applicable contract amendments or rate updates, confirming that no amendment was in effect that would support a lower allowable rate for the dates of service at issue.

We respectfully request that the Synthetic Cigna Appeals Department review the enclosed documentation in its entirety, compare the contracted rates for CPT codes 20561, 28136, and 29769 against the rates applied during adjudication, and identify and correct the discrepancy that resulted in the improper CO-45 denial.

IV. REQUESTED REMEDY

Based on the foregoing, [Provider/Facility Name] respectfully requests that Synthetic Cigna:

1. Overturn the CO-45 denial applied to claim number TEST-CLAIM-00023;
2. Reprocess the claim in accordance with the contracted fee schedule rates applicable to CPT codes 20561, 28136, and 29769 as set forth in the signed provider service agreement; and
3. Issue payment of the improperly denied amount of $2,453.79, plus any applicable interest owed under state prompt-pay statutes or contractual terms.

This appeal is being submitted in advance of the appeal deadline of 2026-07-14. We ask that Synthetic Cigna acknowledge receipt of this appeal and provide a written determination within the timeframe required under the applicable provider agreement and regulatory requirements.

Should additional documentation or clarification be required to resolve this matter, please contact [Provider Contact Name] at [Provider Contact Phone/Email]. We welcome the opportunity to resolve this dispute promptly and amicably.

Thank you for your prompt attention to this matter.

Respectfully submitted,

[Authorized Provider Representative Name]
[Title]
[Provider/Facility Name]
[Address]
[Phone]
[Email]

Enclosures:
- Signed provider service agreement or contract with Synthetic Cigna
- Applicable fee schedule or rate table
- Itemized bill with CPT code-to-charge mapping
- Documentation of contract amendments or rate updates (if applicable)