CO-26: Service dates before coverage started

The payer is telling you the member did not have active coverage with that plan on the dates you billed. In their view, the plan had no financial responsibility yet, so they will not pay for those services. Behind the scenes the eligibility edit is comparing each billed date of service to the coverage effective date on file. Any line or span that falls before that start date hits CO-26 and shifts the balance to contractual, which means you cannot bill the patient under the terms of that denial.

In behavioral health this often hits long-stay levels of care that straddle a coverage start date. Example: a residential or detox admit on 9/29, but the new commercial plan starts 10/1, and billing sends one UB-04 from 9/29 to 10/5, so the early days deny as CO-26. PHP and IOP are also common targets. A patient may enroll self-pay for the first week while waiting for employer coverage to start, but the program forgets to flag that week as self-pay and bills the new plan for the whole episode, triggering CO-26 on those early dates. For MAT and OTP programs that bill weekly or monthly bundles, CO-26 can hit if the bundle period starts before the coverage effective date. Medicaid and MCO changes create another trap, where the behavioral carve-out plan starts mid-month and all behavioral claims before that effective date are the responsibility of a different payer or the state fee-for-service program.

• Confirm the member's exact coverage effective date for that plan using the portal or by calling the payer.
• Compare coverage dates to your admission, discharge, and visit dates, and to the from and through dates billed.
• If coverage actually started earlier than the payer shows, get written proof and request corrected eligibility and reprocessing or submit a corrected claim.
• If another payer covered those earlier dates, bill or rebill the correct payer and handle coordination of benefits as needed.
• If no coverage existed for those dates, review contracts and state rules, then, if allowed, reclassify those days as self-pay and document the decision.
• If only part of a span is before coverage, split the claim at the effective date and appeal for payment of the covered portion with a clear claim correction note.

• Run and document eligibility at intake and again on each change in level of care, verifying exact effective dates.
• Set billing edits so claims cannot go out when any billed date precedes the active coverage period on file.
• Train intake and utilization review staff to align admit dates, authorizations, and financial agreements with coverage start dates and any waiting periods.
• For residential, detox, PHP, and IOP spanning a start date, split service spans in your system so only covered days bill to the payer.