CO-239 denial code
Claim spans eligible and ineligible periods; rebill separate claims
How to fix it
Split the claim at the coverage boundary and submit separate claims for each period.
How to prevent it
Check coverage across the full date span for multi-day services before billing.
In practice
An inpatient stay runs from the twenty-eighth of one month to the third of the next. Coverage changed at the month end, and the claim for the full stay returns CO-239 with instruction to rebill as separate claims.
The payer is telling you exactly what to do, which distinguishes this from the codes that only report a problem. Its liability covers part of the span and it cannot adjudicate a claim reaching beyond that.
Submit one claim for the dates the plan was responsible and separate claims for the remainder to whichever payer covers those dates. Each claim then sits wholly inside one payer's period.
What sits behind it
Splitting is more involved than it sounds for facility claims. Charges have to be allocated to the correct dates, and any per-diem or case-rate methodology has to be applied to each segment, which is not simply a matter of dividing the original claim.
Diagnosis-related group payment complicates it further, since a case rate covering a whole stay does not decompose cleanly into date ranges. Where that applies, the payer's own instruction on how to split takes precedence over any general rule.
The second segment may go somewhere unexpected. A new plan, a state program, or the patient can each be responsible depending on what replaced the coverage, so establishing the successor payer is part of the work rather than an afterthought.
Related codes
Terms used here — Eligibility Verification · Coordination of Benefits · Clean Claim
How we handle it — Claims Management · Eligibility Verification · AR Management
Primary sources
The rules behind CO-239, at the bodies that publish them.
- 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 Coverage Database (LCD/NCD) (opens in a new tab)
Centers for Medicare & Medicaid Services — Searchable national and local coverage determinations. The direct answer to whether a diagnosis supports medical necessity for a given procedure.
- Claim Adjustment Reason Codes (CARC) (opens in a new tab)
X12 — The authoritative, maintained CARC list. Our denial code lookup explains these in plain English; X12 is where the canonical definitions live.
Looking for a different code? Search all 190 CARC and RARC codes
Questions about CO-239
To the dates on which they were incurred, with any per-diem or case-rate methodology applied to each segment separately. It is not a matter of dividing the original claim proportionally, which is why facility splits take more work than professional ones.
A rate covering a whole stay does not decompose cleanly into date ranges, so the payer's own instruction on how to handle the split governs. Ask rather than assume, because a general rule applied to a case-rate claim usually produces a second denial.
It depends on what replaced the coverage — a new plan, a state program, or the patient. Identifying the successor payer is part of the work, and the eligibility record for those specific dates is where the answer is.
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