CARC 151 - Payer Deems Information Submitted Does Not Support This Many/Frequency of Services

What it means

The payer received your claim but decided that the documentation you sent doesn't justify the number of units, visits, or how often the service was performed. This is a medical necessity/utilization denial tied to quantity or frequency, not a coding error.

Common causes

Units billed exceed what the payer's medical policy or LCD/NCD allows for the diagnosis
Documentation doesn't clearly show why repeated services (e.g., therapy visits, imaging, injections) were medically necessary
Frequency of a recurring service (e.g., weekly labs, physical therapy) exceeds payer-defined thresholds without supporting notes
Missing or incomplete progress notes showing patient response to treatment justifying continued/increased services
Claim lacks a required modifier or prior authorization reference tied to the quantity billed
Same service billed multiple times in a short period without clear clinical rationale

How to fix it

Pull the payer's specific medical policy or LCD for the CPT/HCPCS code to confirm frequency/unit limits
Review the clinical documentation to see if it supports the volume of services billed; identify any gaps
If documentation is adequate but wasn't submitted, resend the claim with supporting notes, orders, and progress reports
If documentation is genuinely insufficient, obtain an addendum from the provider clarifying medical necessity for the frequency/units
Verify units billed match what was actually performed and are coded correctly (e.g., correct use of units vs. separate line items)
Check whether prior authorization was required for the quantity/frequency and confirm it was obtained and referenced on the claim

Appeal / resubmit

When appealing, attach the complete clinical record (evaluation, treatment notes, physician orders) that directly ties each unit or visit to a documented medical need. Reference the specific payer policy and explain how the patient's condition met its criteria. If the denial stems from a documentation gap rather than lack of necessity, a corrected claim with an addendum note may resolve it faster than a formal appeal. Keep in mind an appeal does not ensure the claim will be paid, but stronger clinical evidence improves your case.

Related codes

Frequently asked

Does CARC 151 mean my coding was wrong?

Not necessarily. It usually means the payer's review found the documentation insufficient to support the volume or frequency of services billed, not that the codes themselves were incorrect.

Can I just resubmit the same claim?

Resubmitting without adding stronger documentation or correcting the units/frequency is unlikely to change the outcome. Address the underlying documentation or policy issue first.

Is prior authorization related to this denial?

It can be. Some payers require prior authorization for higher unit counts or frequent services; check if that was needed and properly referenced on the claim.

More free billing tools: all denial codes · denial lookup · Medicare fee calculator

This content is informational only and is not billing or legal advice. Always verify with the specific payer's policies and consult a qualified billing or compliance professional for your situation.