CO-256 denial code
Not payable per your managed care contract. The payer isn't citing coverage rules or coding edits — it is citing the deal you signed. Some provision of your participation agreement makes this service, in this context, not separately payable.
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 contract folds this service into another payment — a case rate, a per-diem, a global arrangement that already includes it.
- 2A contractual exclusion: the agreement lists services it will not pay this provider type for.
- 3The service belongs to a different arrangement under the same contract — capitated when billed fee-for-service, or vice versa.
How do I fix a CO-256 denial?
- Get the contract out and find the provision. You cannot evaluate this denial without it — and asking the payer to cite the specific section is a legitimate first move.
- If the provision was misapplied, dispute through the contract's own dispute-resolution process, citing the section. Contract disputes follow the contract's route, not the standard appeal form.
- If the contract really does say so, the write-off is yours and the patient cannot be billed. Flag it for your next contract negotiation instead.
Writing the appeal?
Our free generator drafts a CO-256 appeal letter that opens with the argument above — it runs entirely in your browser, so the claim details never leave your screen. No signup.
Generate the appeal letterHow to stop the next one
Know what your managed care contracts actually say about your top services. The provisions behind this denial were negotiable once and will be again — but only if billing tells contracting which ones are biting.
Our diagnosis scrubber will not catch this one. CO-256 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.
Related denials
- CO-24The charge is covered under a capitation arrangement or managed care plan — meaning fee-for-service payment doesn't apply.
- CO-131A claim-specific negotiated discount was applied — a rate agreed for this claim rather than by your standing contract.
- CO-45Your charge was above the payer's allowed amount, and the difference is a contractual write-off.