CO-256: Service not payable under the managed care contract

What causes CO-256?

• Service excluded from the contract’s covered list
• Service carved out to a different vendor — behavioural health, vision, laboratory and radiology are the usual carve-outs
• Contract requires the service to be delivered by a designated provider
• Billed to the plan when the capitated group holds the risk

How do you fix a CO-256 denial?

1. Read the contract’s covered services and carve-outs before appealing. Most of these are correct denials sent to the wrong entity.
2. Where the service is carved out, bill the carve-out vendor inside its own filing window.
3. Where the contract does cover it, appeal with the contract language cited specifically.
4. Read the group code before any balance is moved to the patient.

Can CO-256 be prevented?

Keep a per-contract summary of carve-outs where billing can see it. Carve-outs are invisible on an eligibility check and are the usual reason for this denial.

A denial like this one is the recurring cost that medical billing outsourcing is built to take off your desk — a dedicated seat working the queue instead of it waiting for whoever has a free hour.

Codes worked the same way

CO-256 is checked against the contract before any work is done. So are these, which is why a queue sorted by recovery route moves faster than one sorted by code number — the same person, in the same system, with the same evidence to hand, clears all of them in one pass.

• CO-45 — Charge exceeds the fee schedule
• OA-23 — Prior payer already adjudicated
• CO-286 — Appeal filed too late
• CO-253 — Sequestration reduction
• CO-B10 — Component already paid
• N381 — Per contract

Specialties that name this among their costliest

These are specialties whose own worst denials include one of this kind. The line under each is the denial they name, quoted from their page so you can see what the link is based on.

• Anesthesia
  Post-op pain blocks bundled into the anesthesia claim
• Ophthalmology
  Retinal imaging and fundus photography done at the same visit, with one line denied as bundled because the record never gives a separate reason for each test.
• Otolaryngology
  The operative note does not state which sinuses were entered on which side, so the sinus surgery lines are bundled together or only one side is allowed.
• Urgent Care
  A global urgent care case rate billed alongside a separate evaluation and management line where the contract pays one or the other, and the second line drops off
• Primary Care
  A preventive visit and a same-day problem visit written up in one undivided note, so the problem visit bundles into the wellness visit and is not paid separately.
• Oncology
  Payer required the drug through its contracted specialty pharmacy, the practice infused from its own stock, and the buy-and-bill claim was denied in full.

What leaving it costs

Working a denied claim costs $57.23 per denied claim in administrative time (source) — before any of it is recovered, and whether or not it ever is.

Payers ultimately pay roughly 90% of claims even while using an initial denial to slow payment (source), so the reason one sits is rarely that nobody knows how to work it. Put your own denial count in.

Questions

Code descriptions are the standard X12 claim adjustment reason and remittance advice remark code text. Payer policies differ, and the payer’s own coverage policy governs any individual claim. This page is working guidance, not legal or clinical advice.