CO-4

CO-4 Denial Code: Modifier Decision Tree & Fix Guide

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A clean, modern flat-style illustration of a medical billing desk from a top-down angle, showing a claim form with a red "denied" stamp next to a laptop screen displaying a branching decision-tree diagram. Soft blue and white color palette, minimal clutter, no readable text on any document, professional editorial illustration style, 16:9 aspect ratio, bright and high contrast for mobile thumbnails.

You pull up the remittance advice and there it is again. CO-4. The procedure code is inconsistent with the modifier used, or a required modifier is missing. You know the claim was clean. The documentation supports the visit. And yet here you are, staring at another denial that isn’t about medical necessity or eligibility at … Read more