Dental insurance denial codes cheat sheet
What the codes on your EOBs actually mean, what usually fixes them, and a follow-up checklist for claims at 30, 60 and 90 days. Free and printable.
What’s inside
- The CARC codes dental offices commonly see, from CO-16 to PR-119, each with a plain-English meaning, the likely fix and the next action.
- What CO, PR, OA and PI mean, and why the group code decides whether you can bill the patient.
- The RARC remark codes that come with them, such as N37 (missing tooth number) and MA04 (primary EOB needed).
- What documentation payers usually want for crowns, scaling and root planing, bridges and implants, endo and extractions.
- Which denials need a corrected claim, which need an appeal, and which are simply the patient’s balance.
- An insurance AR follow-up checklist for claims at 0–30, 31–60, 61–90 and 90+ days.
Who it’s for
Dental office managers, billing coordinators, front-desk teams and practice owners who work insurance claims themselves, especially if your list of unpaid insurance claims (your “aging report”) has a 90+ day column you’d rather not look at.
Rather not do it yourself? Dull is a done-for-you service, not software. We can chase your unpaid claims for you.
Get the cheat sheet
Free. It opens on this page as soon as you send the form. Please don’t include any patient information.
Thanks, it’s yours.
Open it now, then print it or save it as a PDF to keep by the front desk.
Open the cheat sheetBehind on insurance AR? Book a 15-minute call. Dental work is scoped on the call, and no patient data is shared until a BAA is signed.
Frequently asked questions
Which codes does the cheat sheet cover?
About 20 Claim Adjustment Reason Codes (CARCs) that dental offices commonly see on EOBs, such as CO-16, CO-97, CO-252 and PR-119, the four group codes (CO, PR, OA and PI), and 13 Remittance Advice Remark Codes (RARCs) such as N37 and MA04. Each comes with a plain-English meaning, the likely fix and the next action.
Is this an official code list?
No. The codes come from the standard CARC and RARC lists that payers use on EOBs and electronic remittances, shortened into plain English. Payers apply them differently and plans differ, so always read the full EOB and check the payer's own rules and your contract before you act.
Can Dull work our insurance AR?
Yes, often. Dull is a done-for-you service, not software: we chase your unpaid claims for you. Dental work is set up on a 15-minute call, and no patient data is shared until a BAA (business associate agreement) is signed. See Dull for dental practices.