CO-60 denial code
Outpatient services are not covered when performed within a period before or after inpatient services
How to fix it
Confirm the dates and whether the service was genuinely unrelated to the admission. Appeal with documentation where it was.
How to prevent it
Check for recent or upcoming admissions before billing outpatient services for hospitalised patients.
In practice
A patient has preoperative laboratory work three days before a scheduled admission. The hospital bills it as outpatient, and the claim returns CO-60 because the service falls inside the window bundled into the inpatient stay.
Payment policy treats diagnostic services within a defined period before admission as part of the admission itself. The window is commonly three days for acute care hospitals subject to the payment window rule and one day for others.
Where the service was genuinely related to the admission, the correct route is to include it on the inpatient claim rather than appeal the outpatient denial. Where it was clinically unrelated, the appeal attaches documentation establishing that separation.
What sits behind it
The rule exists to prevent unbundling a single episode of care into separately paid components, and it is applied automatically by date proximity rather than by clinical judgement. That means genuinely unrelated services get caught, and the appeal has to supply the judgement the edit could not.
Post-discharge services can trigger the same treatment where they relate to the admission, particularly readmissions and follow-up falling inside a defined window. CO-249 covers the readmission case specifically and is worth distinguishing when it arrives.
For practices billing professional services around a hospitalisation, the practical control is knowing the patient's admission status before billing. A quick check for a recent or scheduled admission costs less than the denial and the rework it generates.
Related codes
Terms used here — NCCI Edits · Denial · Revenue Cycle Management
How we handle it — Claims Management · Denial Management · Revenue Cycle Management
Primary sources
The rules behind CO-60, at the bodies that publish them.
- NCCI Policy Manual for Medicare Services (opens in a new tab)
Centers for Medicare & Medicaid Services — The reasoning behind the edits, chapter by chapter. Where the edit files tell you two codes conflict, this explains why — which is what an appeal has to address.
- National Correct Coding Initiative (NCCI) edits (opens in a new tab)
Centers for Medicare & Medicaid Services — The procedure-to-procedure and medically-unlikely edits behind most bundling denials. Checking these before submission prevents the denial entirely.
- 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-60
Commonly three days for acute care hospitals subject to the inpatient prospective payment system and one day for hospitals and units excluded from it. Diagnostic services within that window, and related non-diagnostic services, are treated as part of the admission.
Yes, but the burden is on you to show the separation. The edit applies by date proximity and cannot assess clinical relationship, so the appeal has to attach documentation establishing that the service addressed something distinct from the reason for admission.
The window rule is a facility payment policy, but professional services around a hospitalisation face related bundling questions and can attract this code. Checking admission status before billing outpatient services for recently or shortly-to-be hospitalised patients avoids most instances.
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