CO-24 denial code
The charge is covered under a capitation arrangement or managed care plan — meaning fee-for-service payment doesn't apply. Most often this is a Medicare claim for a patient who is actually enrolled in a Medicare Advantage plan.
CO — Contractual Obligation. The write-off is yours. You agreed to it in your contract with the payer, and you cannot bill the patient for it.
Why you got it
- 1The patient is in a Medicare Advantage plan and the claim went to traditional Medicare, which correctly answers that it no longer pays for this patient.
- 2The service falls under a capitation agreement — a monthly per-member payment to a PCP, IPA, or medical group already covers it, so a separate claim has nothing to attach to.
- 3The patient switched into or out of a managed care plan and the enrollment records lag reality.
How do I fix a CO-24 denial?
- Verify enrollment for the date of service and find out who actually holds the risk: the MA plan, the medical group, the IPA.
- Rebill the correct entity. An MA plan claim goes to the plan, not to Medicare; a capitated service may need to go to the group that holds the capitation.
- If you are the capitated provider, there is nothing to collect — the monthly payment was the payment. Writing this off correctly matters for your books.
How to stop the next one
Eligibility checks that surface plan enrollment, not just 'active coverage'. Medicare Advantage enrollment is exactly the kind of fact a yes/no eligibility ping hides and a proper check reveals.
Our diagnosis scrubber will not catch this one. CO-24 is driven by procedure codes, modifiers, or eligibility rather than by the diagnosis set — and procedure-side checking needs CPT codes, which aren’t included yet. We would rather tell you that than sell you a tool that quietly misses your most common denial.
If denials like this are a volume problem rather than a one-off, the denial management page explains how the paid workspace catches the coding causes on every claim, and the free ICD-10-CM lookup shows the coding notes behind any diagnosis code on the remittance.