CO-252 — Attachment / documentation required
Claim-adjustment reason code 252 · typically reported as CO-252 or OA-252
What it means
The payer wants supporting documentation before it will adjudicate — a softer cousin of CO-226 that arrives up front.
Why DME claims hit it
- Items the payer always pends for review (high-dollar rehab equipment, NOC codes)
- Claims missing required attachment indicators
How to fix it
- Submit the requested documentation per the remark-code instructions; for chronic offenders, send documentation proactively with the claim
Appeal posture
Not yet a final denial — respond to the request; appeal only after a post-review denial.
Related denial codes
CO-226 — Requested records not received from providerCO-16 — Claim lacks information or has a submission errorCO-50 — Not deemed medically necessary
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