What does denial code CARC 151 mean on a dental claim, and can it be appealed?

On a dental remittance, CARC 151 means: The quantity or recurrence billed is greater than the submitted record supports under the payer's review. X12 assigns it no group code, so the group code on the remittance is the payer's choice under its own contract and it, not the CARC, decides who is assigned the balance. Remark codes verified with it: N362. Dentovio's appealability verdict — depends: check the facts first. A valid contractual frequency limit controls. Contestable cases include history errors—the prior service was miscoded, belonged to another provider, or fell outside the window—and replacement exceptions the policy expressly allows.

Necessity, frequency, and alternate benefits · Last verified 2026-08-30

CARC 151 denial code on dental claims

Independent publisher · Drafted with AI assistance, verified against primary sources · Credentialed review pending

CARC 151 is the “Frequency not supported” code on a dental remittance. Whether it can be contested depends on the facts; run the checks below first.

Group code: X12 places no group-code restriction on 151. A group code always travels with a CARC, and it — not the CARC — assigns financial responsibility, so read the one on your remittance rather than assuming. Offices commonly write this one as CO 151; that is search shorthand, not a statement that the payer will use CO.

Registry entry: X12 Claim Adjustment Reason Code 151 — active, with no deactivation date. Read on the list published 2025-11-01.

Verdict

Depends — check the facts first

A valid contract term may control, while a factual error may be contested. Run the checks on this page before using the appeal window.

A valid contractual frequency limit controls. Contestable cases include history errors—the prior service was miscoded, belonged to another provider, or fell outside the window—and replacement exceptions the policy expressly allows.

The appealability verdicts on these pages are Dentovio's editorial classification. No standards body or payer publishes an appealability taxonomy: X12 defines what a code means, not what to do about it. Each verdict is built from the code's own mechanics and the payer and federal documents cited on the page, and it is a starting point for triage rather than a prediction of any outcome.

What it means in dental

The quantity or recurrence billed is greater than the submitted record supports under the payer's review.

This can involve prophy and exam intervals, SRP once per quadrant per a stated multi-year window, or a crown replacement clock. The payer is saying the count or interval exceeded its rule.

What to do

1.Request the payer's service history for the code — verify the prior date and provider it counted
2.Check the plan's stated interval against the actual dates of service
3.If the policy allows exceptions, appeal under the exception with the qualifying documentation

Remark codes verified with this CARC

X12 defines no CARC-to-RARC pairings. Each combination below is either a payer's own published crosswalk — true for that payer's internal reason code, not as a general rule — a CAQH CORE-required combination, or a remark whose registry meaning describes this adjustment.

N362 · Seen in a payer's own published crosswalk

This payer caps the days or units it will accept on a line, and the claim went over that cap.

What to do: Check the payer's stated per-day or per-period maximum for the code before resubmitting anything.

MassHealth's crosswalk pairs 151 with N362 — not with M53, which it uses on CARC 16. CARC 151 appears only twice in that whole document, and the other row carries no remark code at all.

MassHealth — Claim Adjustment Reason Codes and Remittance Advice Remark Codes crosswalk (posted 2026-02-12) — EOB 8215, p. 66; EOB 9055, p. 73

Appeal routes, by plan funding

Fully-insured route

State insurance law (prompt-pay statutes + plan appeal terms)

Check the state's prompt-pay rule first — an overdue clean claim may already be accruing interest without any appeal. Then run the policy's internal appeal, and escalate to the state insurance department where deadlines were missed.

Self-funded (ERISA) route

29 CFR 2560.503-1

Appeal in the patient's name (or with an authorized-representative form), demand the claim file and the specific internal rule relied on, and hold the plan to the 30/60-day clocks in writing. Before counting on a state remedy, read that state's own scope provision: several state prompt-pay and external-review statutes reach only insurers and HMOs by their terms, so they do not extend to a self-funded plan.

Medicaid managed care route

42 CFR 438.402 / 438.408

First classify the dispute. For an enrollee benefit denial, track two clocks in order: 60 days to the plan appeal, then (after the resolution notice) the state's 90–120-day fair-hearing window, with written consent before a provider acts for the enrollee. For a provider payment or contract dispute, use the provider contract and state Medicaid program process instead. For members under 21, federal EPSDT coverage rules also matter.

Documentation pages for this denial family

The durable fix is submitting what the payer's published criteria ask for the first time:

Read with this code

CARC 119 — Benefit maximum reached

Sources

X12 Claim Adjustment Reason Codes (external code list 139) — list updated 2025-11-01
X12 Remittance Advice Remark Codes (external code list 411) — list updated 2026-07-01
45 CFR 162.1602 — HIPAA adoption of the 835 remittance standard that carries these codes
MassHealth — Claim Adjustment Reason Codes and Remittance Advice Remark Codes crosswalk (posted 2026-02-12) — EOB 8215, p. 66; EOB 9055, p. 73
MassHealth — Claim Adjustment Reason Codes and Remittance Advice Remark Codes crosswalk (posted 2026-02-12)