Denial Code 23: What It Means and How to Appeal
If you are looking up code 23, you are holding a denial. Denials like this are frequently overturned when the appeal supplies the missing element and cites the plan's own rules. We do not publish a percentage for this category because we will not show a number we cannot back. Appeal before the deadline.
Denial code 23 means: The impact of prior payer adjudication, including payments and adjustments.
Why it happens: Coordination of benefits with another payer.
Is it appealable? Yes. Denials like this are frequently overturned when the appeal supplies the missing element and cites the plan's own rules. We do not publish a percentage for this category because we will not show a number we cannot back.
What to send: the missing element for this code, a short appeal letter citing the plan's claims-procedure rules, and any clinical support.
Note: code 23 may appear on your remittance with a group-code prefix such as PR-23 (patient responsibility) or CO-23 (contractual obligation). The denial reason is the same.
Expert analysis: how this denial is overturned
A coordination-of-benefits denial means the plan believes another payer is primary, or it adjusted your claim based on what a prior payer did. These are ordering problems, not coverage refusals. The fix is to establish the correct order of benefits: confirm which plan is primary using your coverage dates and the standard COB rules, then provide the primary payer's explanation of benefits so the secondary plan can pay its share. Even though the dispute is administrative, it is still an adverse benefit determination subject to the full-and-fair-review requirement of 29 CFR 2560.503-1(h)(1), and you may request the basis the plan used under 29 CFR 2560.503-1(g)(1)(v). You generally have at least 180 days to appeal (29 CFR 2560.503-1(h)(3)(i)). Note that a pure benefit-ordering dispute usually does not involve medical judgment, so external review under 45 CFR 147.136 may not apply. Honest odds: COB denials resolve well once the correct primary EOB is on file.
Sources: 29 CFR 2560.503-1 (ERISA claims procedure), 45 CFR 147.136 (ACA internal and external review), and the X12 Claim Adjustment Reason Code standard.
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Appeal my code 23 denialFrequently asked questions
- What does denial code 23 mean?
- The impact of prior payer adjudication, including payments and adjustments.
- Is denial code 23 appealable?
- Yes. Denials like this are frequently overturned when the appeal supplies the missing element and cites the plan's own rules. We do not publish a percentage for this category because we will not show a number we cannot back.
- What should I send to appeal a code 23 denial?
- Supply the missing element for this code, a short appeal letter citing the plan's claims-procedure rules, and any clinical support. Apellica prepares and files this for you.