CO 26: Service Before Coverage Began
Service fell before coverage started.
Re-verify, then rebill the correct payer or the patient.
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What CO 26 means
CO: Contractual obligation. The provider absorbs it and cannot bill the patient.
So the balance cannot move to the patient. Either the appeal recovers it or the practice absorbs it. That makes the appeal decision the whole decision on this line.
The same code, a different prefix. 26 also arrives as PR 26. The reason for the denial is the same. The prefix decides who pays for it, so the next step is not the same. If your remit says PR 26, read that page instead.
Is It Worth Appealing?
Usually lost. Recoverable only with unusual evidence. Triage by dollar value.
How to Appeal CO 26, Step by Step
Re-verify, then rebill the correct payer or the patient.
- 1Step 1: Read the remark code. Find the remark code printed next to CO 26 on the 835 or EOB. It says what the payer wants back.
- 2Step 2: Take the first action. Re-verify, then rebill the correct payer or the patient.
- 3Step 3: Send the appeal before the deadline. Send it to the payer with the claim, the denial and the documentation, inside the payer's appeal window. See what an appeal letter must contain and the filing limits by payer.
Free: the Denial Code Appeal Playbook. 53 codes on one sheet: appeal, fix and resubmit, or let it go, and what to attach. Get the playbook
CO 26 description
Service fell before coverage started.
Service fell before coverage started. So the balance cannot move to the patient. Either the appeal recovers it or the practice absorbs it. That makes the appeal decision the whole decision on this line.
This is our plain-English wording, not the official X12 text. X12 asserts copyright over the published descriptions, so we write our own and say what it means for the money rather than restating the code.
Where this comes from. This is our own reading of the code, not the payer's and not a copy of the standards text. We classify it from how these denials actually resolve. Where we are unsure, we say so rather than guessing.
Related Codes
CO 185
The rendering provider is not eligible to perform the service billed.
Read the CO 185 pageCO 242
The provider was out of network, or not the patient's assigned primary care provider.
Read the CO 242 pageCO 27
Coverage had ended on the date of service.
Read the CO 27 pageCO B7
The provider was not certified or eligible for this service on that date.
Read the CO B7 page
Your Questions Answered
What does CO 26 mean?
Service fell before coverage started. Contractual obligation. The provider absorbs it and cannot bill the patient.
Can you appeal CO 26?
Usually lost. Re-verify, then rebill the correct payer or the patient.
How do I appeal a CO 26 denial?
Step 1: Read the remark code. Find the remark code printed next to CO 26 on the 835 or EOB. It says what the payer wants back. Step 2: Take the first action. Re-verify, then rebill the correct payer or the patient. Step 3: Send the appeal before the deadline. Send it to the payer with the claim, the denial and the documentation, inside the payer's appeal window.
Most searched: CO 97 · CO 96 · OA 23 · PR 204 · CO 109 · CO 197 · CO 45 · CO 50
How Much of This Is Sitting in Your Write-Off Pile?
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Upload your denial summary for the last 90 days. 4 columns: payer, CARC code, count, billed amount. You get back which were winnable and what they were worth.