Appeal — TEST-CLAIM-00004

Date: [Date of Submission]

Appeal and Grievance Department
Synthetic UHC
[Payer Address]

Re: Formal Appeal of Claim Denial — CO-29 Timely Filing
Claim Number: TEST-CLAIM-00004
Date of Service: February 27, 2026
Denial Date: May 4, 2026
Denied Amount: $1,683.00
Procedure Code(s): CPT 31579
Diagnosis Code(s): M17.49, K21.58

Dear Appeals Review Department,

On behalf of [Hospital/Facility Name], we write to formally appeal the denial issued by Synthetic UHC on May 4, 2026, for Claim Number TEST-CLAIM-00004, in the amount of $1,683.00. The claim was denied under adjustment reason code CO-29, asserting that "the time limit for filing this claim has expired." We respectfully contest this determination and request that Synthetic UHC reverse the denial and reprocess the claim for full payment of the denied amount.

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I. BASIS FOR APPEAL

The CO-29 denial is not supported by the facts of record. The date of service was February 27, 2026, and the denial was issued on May 4, 2026 — approximately 66 days following the date of service. Standard contractual timely filing windows in provider agreements with commercial payers, including those consistent with Synthetic UHC's own published policies, commonly range from 90 days to 12 months from the date of service. A denial issued only 66 days post-service, on its face, raises a strong presumption that this claim was filed within the applicable contractual deadline.

As documented in the enclosed hospital billing records and proof of timely claim submission, the claim for CPT 31579 rendered on February 27, 2026, was submitted to Synthetic UHC within the contractually required filing period. The enclosed submission confirmation records — including the UB-04 with timestamp and/or electronic acknowledgment of receipt — demonstrate that the claim was presented to the payer in a timely and compliant manner. Accordingly, the CO-29 denial lacks a factual basis and must be overturned.

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II. SUPPORTING DOCUMENTATION

In support of this appeal, we have enclosed the following documents:

1. Hospital billing records reflecting the date of service (February 27, 2026) and the initial claim submission date.
2. Proof of timely claim submission, including the UB-04 with electronic timestamp and/or electronic submission confirmation receipt.
3. The Explanation of Benefits (EOB) or denial notice reflecting the denial date of May 4, 2026, and the CO-29 denial code.
4. Documentation of any payer correspondence, resubmissions, or administrative communications related to this claim.
5. Evidence of any system or administrative delays, if applicable, including billing department logs or electronic health record system records.
6. Applicable payer contract provisions or Synthetic UHC policy language governing the timely filing window and any recognized exceptions.

These documents collectively establish that the claim was submitted within the applicable timely filing period and that the CO-29 denial is inconsistent with both the submission record and the payer's own contractual filing requirements.

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III. POLICY ANALYSIS

Under the payer's timely filing policy, a CO-29 denial is only appropriate when a claim is submitted after the expiration of the contractually established filing deadline. Given that the denial was generated a mere 66 days following the date of service — well within the range of most standard 90-day to 12-month timely filing windows — it is the position of [Hospital/Facility Name] that this denial was issued in error. Should Synthetic UHC contend that a shorter filing window applies to this claim, we respectfully request that the payer identify the specific contractual provision upon which it relies, along with the precise deadline date and the date on which the claim was allegedly received, so that this facility may evaluate and respond accordingly.

Furthermore, to the extent that any delay in submission occurred as a result of payer system error, administrative processing issues, or other circumstances beyond the control of this facility, the enclosed documentation supports the application of any applicable exception provisions recognized under the provider agreement or applicable state insurance regulations.

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IV. REQUESTED REMEDY

[Hospital/Facility Name] respectfully requests that Synthetic UHC:

1. Reverse the CO-29 timely filing denial for Claim Number TEST-CLAIM-00004;
2. Reprocess the claim in full pursuant to the applicable provider agreement and fee schedule; and
3. Issue payment of the denied amount of $1,683.00.

This appeal must be resolved no later than the appeal deadline of August 2, 2026. Should additional information be required to complete the review of this appeal, please contact [Hospital/Facility Billing Contact Name] at [Phone Number/Email Address] at your earliest convenience.

We appreciate Synthetic UHC's prompt attention to this matter and trust that a thorough review of the enclosed documentation will result in the appropriate reversal of this denial.

Respectfully submitted,

[Authorized Signatory Name]
[Title]
[Hospital/Facility Name]
[Address]
[Phone Number]
[Date]