CO-24 Denial Code: Service falls under a capitation or managed care plan

What CO-24 means

CO-24 means the payer believes this service is already covered by a capitation arrangement or belongs to a managed care plan rather than to the payer you billed. The classic case is a Medicare Advantage enrollee whose claim went to Original Medicare - Medicare sees the Part C enrollment and denies, and the fix is resubmitting to the MA plan before its own filing deadline. The other branch applies to capitated providers: if the service is inside your per-member-per-month payment, billing it fee-for-service will always deny, and only services carved out of the cap can be billed separately. Either way the amount is not patient-billable - the money comes from routing the claim to the correct plan or is already inside your capitation payment.

Common causes

• The patient is enrolled in a Medicare Advantage plan but the claim was billed to Original Medicare.
• A Medicaid managed-care enrollee's claim was sent to state fee-for-service Medicaid.
• The service is included in your capitation agreement but was billed fee-for-service.
• Eligibility was not rechecked after the start of the year, when many patients switch to or between Medicare Advantage plans.
• The patient presented the Original Medicare card instead of their Advantage plan card, and registration keyed the wrong coverage.
• A service you believed was carved out of the capitation arrangement is actually inside it.

How to fix it

• Run a current eligibility check to identify the managed care plan, its payer ID, and the enrollment effective dates.
• Resubmit the claim to the correct plan promptly - the managed care plan's own timely-filing clock has been running since the date of service.
• If you are capitated with the plan, check the contract's covered-services list; bill fee-for-service only for services explicitly carved out, and attach documentation.
• If eligibility shows the patient was not enrolled in the managed care plan on the date of service, send the denying payer proof and request reprocessing.
• Update the patient's coverage record so future claims route correctly.

How to prevent it

• Verify eligibility at every visit, and re-verify every January when Medicare Advantage plan changes take effect.
• Ask Medicare patients specifically whether they have an Advantage plan - the Original Medicare card alone is not proof of fee-for-service coverage.
• Flag capitated patients and the capitation covered-services list in your PM system so fee-for-service claims for capped services never go out.
• Load correct payer IDs for each managed care plan and audit routing rules after plan-year changes.

Appeal potential