Paste a denial code. Know what to do next.

D3rx is the denial-code copilot for the front desk of a small physician practice. Paste the code from your remittance, like CO-45, PR-204, or N130, and get plain English: why it denied and the next billing step.

Try formats like CO-45, co 45, 45, N130, or PR-204. Lookup happens in your browser from the static D3rx denial-code library.

CO-45Charge is above the payer's allowed amount.PR-204A service or drug is not covered under the patient's plan.N130The claim needs correction before it can be worked.
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Provider-side reference, not a patient billing app.

Denial code library →CPT codes →Modifiers →Glossary →Prior auth →