CO-27 denials: when coverage ends or moves
CO-27 identifies a coverage-termination adjustment. A replacement plan, Medicaid reassignment, or retroactive change can explain what happened and where the claim belongs.
CARC 27 means the payer treated the expense as occurring after coverage terminated. With the CO group code, it assigns the adjustment to the provider. It does not establish that every possible payer lacked coverage on that date. X12 adjustment reason codes.
Coverage on the date of service is what matters. Today's active or inactive status can answer a different question. A patient may have changed employers, moved between Medicaid arrangements, or had an enrollment error corrected after the visit.
Separate the events before choosing a fix
| What happened | What to establish | Next action |
|---|---|---|
| Coverage ended without a replacement | Effective dates and whether the payer record is correct | Resolve the denial and applicable financial responsibility |
| The patient changed plans | Replacement payer and coverage on the service date | Verify benefits, authorization, and the new filing deadline |
| Medicaid administration changed | State eligibility and service-specific managed-care responsibility | Send the claim to the responsible entity |
| Coverage changed retroactively | Affected dates, claims, and any payment reversals | Reconcile the takeback and review coverage or appeal options |
For Medicaid, check the assigned plan and any services retained by fee-for-service Medicaid. Managed-care enrollment does not mean every service belongs to the MCO. Use the state's current rules for the member and service.
If the patient reports a new plan but the details are missing, insurance discovery can help identify candidate coverage. Verify a discovered plan before attaching it to a claim.
The denial is not permission to bill the patient
CMS distinguishes CO, which assigns financial responsibility to the provider, from PR, which assigns it to the patient. CMS remittance guidance explains the group-code role.
Avoid a blanket rule for other group codes. Read the adjustment and remark together with the contract and benefit rules. Where liability remains unresolved, keep the balance in review.
Treat a recoupment as a separate reconciliation task
A retroactive termination can produce a claim reversal, a later offset, or both. Preserve the payer's notice and trace the adjustment to the affected service. A provider-level adjustment is not necessarily a termination, and a short deposit alone does not identify the cause.
Use the remittance references and claim history to reconcile the takeback. The 835 provider-level adjustment guide explains the accounting path.
Work the coverage and filing dates together
- 01Verify the service dateConfirm enrollment dates, member details, and the payer's explanation.
- 02Locate responsible coverageReview replacement plans, Medicaid assignment, and payer order.
- 03Check deadlinesRead the responsible payer's filing and review rules, including any exceptions.
- 04Act and retain evidenceSubmit a supported claim, correction, or appeal and retain the acknowledgments.
For a treatment course, repeat eligibility checks before later services and when insurance information changes. Compare the new evidence with the previous result. Coverage marked active under a different plan needs an owner and a billing decision.
How Foresight helps
Foresight compares stored coverage snapshots and identifies changes in payer, plan, coverage dates, and other benefit details. It links detected changes to affected submitted claims and brings those claims into review. Staff receive the changed evidence with the work it affects.
Insurance discovery supports the search for replacement coverage. Remittance review supports the separate task of tracing reversals and offsets. Keeping those tasks connected helps the team resolve the payer question before an unresolved balance reaches the patient.
Related payer-order problems are covered in the coordination-of-benefits guide.
01Can a CO-27 be appealed?
Yes, when the facts or applicable rules support review. Confirm the service date, enrollment record, payer responsibility, and deadline before choosing between an appeal and a claim to another payer.
02Does a new plan automatically owe the claim?
No. Verify coverage for that service and date, provider participation, required authorization, and filing requirements.