Claims · Updated 2026-09-08 · 5 min read
What is the difference between a denied and a rejected dental claim?
A rejected claim never reached adjudication and carries no CARC — correct and resubmit. A denied claim was judged and can be appealed. The fixes are opposite.
A rejected claim and a denied claim are different events with opposite fixes, and most dental software labels both "denied". A rejection never reached adjudication: it bounced at the front door because information was missing or invalid, and its reason arrives on an electronic claim acknowledgement rather than on an EOB. There is no Claim Adjustment Reason Code, no remark code, no Explanation of Benefits and nothing to appeal — the payer has not decided anything. The fix is always to correct the claim and resubmit. A denial is a payer judgment on a claim the payer accepted and processed: it arrives on the EOB with a reason code, a group code saying who absorbs it, and an appeal route. Treating the second as the first resubmits a claim the payer already judged; treating the first as the second files an appeal against a decision that was never made.
What we measured
| denial reason as it reached the office | denied lines | practices | payers | share of denials |
|---|---|---|---|---|
| Claim submission error | 634 | 24 | 19 | 1.0% |
| Patient not eligible on the date of service | 1,908 | 31 | 98 | 2.9% |
| Missing medical documentation | 1,815 | 33 | 58 | 2.8% |
| Missing plan documentation | 307 | 16 | 26 | 0.5% |
Denied lines are lines paid at $0 with a stored reason on an EOB, all dates: what we saw across 37 dental practices and 170+ payers, measured September 2026.
Read what is missing from that table. Rejections are not in it and cannot be, because a rejection produces no EOB line to count. Everything above is a claim the payer accepted, processed and refused — including the top row, which looks like a rejection and is not. A claim submission error that reaches the office as a reason code on an EOB was adjudicated with the error in it, and the office's next move is a corrected claim rather than an appeal even though the paperwork says "denied".
What the carriers' own documents say
The commonest way a dental secondary claim gets rejected at one carrier that publishes the rule is arithmetic. The BCBS Alabama eClaims Reference Guide for Dental Secondary claims (form code PRV20720-2403, carrier-wide) states that adjustment reason codes come from the standard "Reference for External Code Lists" and that line-level adjustments plus the primary payer information amounts must equal the total amount of the claim. Where the primary's payment, its adjustments and its write-off do not add up to the billed total on every line, the secondary claim rejects before anyone looks at the benefit. Paper claims are not accepted, so the secondary must be filed electronically too.
Delta Dental's crosswalk shows the other side — the same data problems arriving as a denial with a code, after adjudication:
"Benefits could not be determined because of missing/conflicting information. Please submit a new claim or pre-treatment estimate with the appropriate procedure code, arch, quadrant, tooth number, and/or surface code information." (policy code 161)
"Benefits could not be determined because the submitted procedure number is not recognized or is no longer an accepted, standardized procedure code." (policy code 117)
Both from Delta Dental — Policy ID Mapping for CARC/RARC Health Care Policy Codes, pinned at Delta Dental of California network scope. Note the instruction inside both: submit a new claim. That is a rejection's fix arriving inside a denial's paperwork.
Delta adds one practical rule for the resubmission, repeated across its documentation-request codes:
"To prevent delays in processing, please do not attach a copy of this EOB to the new claim."
There is a third state, and it is neither. Cigna's own two-letter code S3 marks a claim still with a reviewer — a pend, not a decision. An office reading a pend as a denial writes off money the payer has not yet ruled on.
Why it depends on the contract
The distinction decides which clock is running and which lane the work goes into. A rejection leaves the filing deadline running as though nothing was ever sent, because nothing was received — so a claim rejected twice can expire while the office believes it is under appeal. A denial usually starts a separate appeal window, and the carrier's ladder and its deadline are set by the participation agreement and by state law, not by the code.
Some carriers also route these differently on purpose. A timely-filing denial can belong in a provider dispute track rather than the appeals track at the same carrier, and a submission filed in the wrong lane is not decided, it is dropped.
What to do
- Check where the reason came from before deciding anything. A reason on an EOB with a group code and a reason code is a denial; a reason with no EOB behind it is a rejection.
- On a rejection, correct the named field and resubmit as a fresh claim. There is no appeal and asking for one costs the time the filing deadline is spending.
- On a secondary claim, reconcile the line arithmetic before sending. The primary's payment, its adjustments and its write-off must equal the billed amount on each line.
- On a denial, read the group letters to see who absorbs it, then the remark code to see whether the payer wants evidence or a corrected field.
- Do not write off a pend. A code meaning "with a reviewer" is a claim in progress, and the money is still live.
- Record the two outcomes separately in the practice management system. A single "denied" bucket hides which half of the work is corrections and which half is appeals, and they are done by different people at different speeds.
Numbers last refreshed September 2026.