Official CARC description: “Payment adjusted because the payer deems the information submitted does not support this many/frequency of services.” Here’s what it actually means, why it fires, and how to get the claim paid.
Too many units or visits for the payer's policy — MUE limits, frequency caps (one screening per year), or utilization edits. Recoverable when the quantity was clinically real and documented.
Liability group: CO = Contractual Obligation — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.
Also written: CO-151, CO151, “denial code 151”, “151 denial code” or “reason code 151” — same CARC, different ERA formatting.
Check the MUE value and its adjudication indicator for the CPT
If billing style was wrong (units vs modifiers): corrected claim
If quantity is real: appeal with records showing each unit's necessity
Track frequency-capped services at scheduling so patients aren't booked into denials
Appeal with documentation itemising every unit (times, sites, medical need). For MUE denials with adjudication indicator 3, per-line documentation review is explicitly available — use it.
Fill in the denial facts — use placeholders, never real patient data (the letter keeps [PATIENT NAME]-style fields so you can merge real details privately). A payer-ready draft with an enclosure checklist comes back in ~20 seconds.
Your appeal letter draft will appear here.
The official CARC description for CO 151 is: “Payment adjusted because the payer deems the information submitted does not support this many/frequency of services.” In practice: Too many units or visits for the payer's policy — MUE limits, frequency caps (one screening per year), or utilization edits. Recoverable when the quantity was clinically real and documented.
Denial code 151 under the CO group (Contractual Obligation) means: Payment adjusted because the payer deems the information submitted does not support this many/frequency of services. The number is the reason; the CO prefix decides who is liable — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.
Yes. CO 151, CO-151, CO151 and “denial code 151” are the same CARC — clearinghouses, payer portals and PM systems just print it differently. Only the group prefix (CO, PR, OA or PI) changes the meaning, because it changes who has to absorb the amount.
CO stands for Contractual Obligation — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.
Appeal with documentation itemising every unit (times, sites, medical need). For MUE denials with adjudication indicator 3, per-line documentation review is explicitly available — use it.