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Analyze My Document — FreeThe most important things to know before you file any appeal.
CO-50 means "not medically necessary" — the most common denial code in health insurance. It's also one of the most overturnable. Here's exactly what it means and how to challenge it.
Read the guide →A full walkthrough of the internal appeal process — what to include, what to say, what your insurer is legally required to do, and how to escalate if your first appeal fails.
Read the guide →Federal law requires insurers to cover mental health the same way they cover physical health. Most people don't know this. Most insurers count on that. Here's how to use it.
Read the guide →Prior auth denials are among the fastest-growing insurance disputes. Here's what it means, why insurers require it, and how to challenge a denial with a medical necessity argument.
Read the guide →Click any category to explore guides for your situation.
Each state has its own appeal deadlines, insurance commissioner processes, and consumer rights protections. Our state guides cover the specifics that matter for your location.
The insurance system runs on codes. We translate them — and tell you exactly what to do about each one.
| Code | What It Means | What to Do | Overturn Likelihood |
|---|---|---|---|
| CO-50 | Not Medically Necessary | Challenge with medical necessity documentation and clinical guidelines | Often Overturned |
| PR-96 | Non-Covered Charge | Review policy language — exclusions must be explicitly stated | Situational |
| CO-4 | Procedure/Modifier Mismatch | Confirm correct modifier and request corrected claim resubmission | Often Overturned |
| CO-97 | Bundling / Unbundling Issue | Technical coding challenge — requires specific CPT unbundling argument | Technical Challenge |
| CO-167 | Diagnosis Not Covered | Provide clinical documentation linking diagnosis to procedure necessity | Strong Appeal Grounds |
| CO-151 | Frequency Limit Exceeded | Submit progress notes and functional outcomes supporting continued care | Often Overturned |
| CO-197 | Prior Authorization Missing | Request retroactive authorization or cite an emergency exception | Situational |
| CO-119 | Benefit Maximum Reached | Verify the visit count and benefit category against your plan documents | Situational |
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Analyze My Document — Free The answer might be better than you think.