CO-201 denial code
Patient is responsible through a set aside arrangement
How to fix it
Bill the set-aside administrator or the patient per the arrangement's terms.
How to prevent it
Identify set-aside arrangements at registration for workers compensation patients.
In practice
A patient settled a workers compensation claim two years ago with a portion allocated to future medical costs. Treatment for the related injury returns CO-201, pointing at that set-aside.
A set-aside is a fund carved out of a settlement to pay future injury-related care before any other payer becomes liable. It exists precisely so that Medicare or a health plan does not pay for care the settlement already funded.
Billing the set-aside administrator, or the patient where the fund is self-administered, is the route. Establishing which arrangement applies is the first question, because self-administered funds behave very differently from professionally administered ones.
What sits behind it
Self-administered set-asides create the most difficulty. The patient holds and manages the money themselves, must keep records of expenditure, and is expected to pay providers directly — a responsibility many patients do not fully understand until a bill arrives.
The fund is finite and only covers care related to the settled injury. Once exhausted and properly documented as exhausted, the ordinary payer becomes liable, and the exhaustion documentation is what the payer will require before accepting the claim.
Identifying these arrangements at registration is the practical control. Asking whether an injury was subject to a workers compensation or liability settlement takes moments and prevents an account routing to the wrong payer for months.
Related codes
Terms used here — Coordination of Benefits · Patient Responsibility · Denial
How we handle it — AR Management · Patient Collections · Denial Management
Primary sources
The rules behind CO-201, at the bodies that publish them.
- Workers' compensation medical billing (opens in a new tab)
US Department of Labor, OWCP — Federal workers' compensation fee schedule and billing requirements. State programs differ, but the structural rules are the same: a separate payer with its own schedule.
- Medicare Secondary Payer Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — When Medicare pays second, and to whom the claim goes first. Coordination-of-benefits denials are resolved here rather than with the patient.
- Medicare Claims Processing Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — The operative manual for how Medicare claims must be coded, submitted, adjusted and appealed. When a payer policy and a vendor's advice disagree, this settles it.
Looking for a different code? Search all 190 CARC and RARC codes
Questions about CO-201
A portion of a workers compensation or liability settlement allocated to pay future medical costs related to the injury. It has to be exhausted on that care before Medicare or a health plan becomes liable, which is why claims route to it first.
The patient, who holds and manages the fund themselves and is expected to pay providers directly. Many patients do not fully understand that responsibility until a bill arrives, so an explanation alongside the statement usually helps.
The ordinary payer becomes liable, but it will want documentation that the fund is exhausted before accepting the claim. Obtaining that documentation from the administrator, or from the patient's records where self-administered, is the step that unlocks payment.
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