CO-151: Payment adjusted because information does not support this many/frequency of services
CO-151 is a utilization denial. The plan says you had too many of a service in too short a time. Some frequency limits are hard rules; others allow medical-necessity exceptions.
What your letter emphasized
- The clinical reasoning for the additional frequency
- Whether the plan document allows a medical-necessity exception to the frequency limit
- Applicable clinical guidelines that support the frequency
- The specific plan provision the frequency limit is drawn from
- Any prior treatment history that necessitates the additional frequency
Common CO-151 scenarios
- Physical therapy visits exceeding the plan's per-condition or per-year cap
- Chiropractic visits exceeding the plan's per-year cap
- Mental health therapy sessions exceeding a per-year cap (MHPAEA implications, see below)
- Prescription refills filled too early (30-day supply rules)
- Imaging studies repeated within a plan-defined window
- Injections or infusions given more often than the plan's utilization criteria allow
What the insurer's likely response is
Reversal on medical necessity. If your provider documents that the additional frequency is medically necessary and the plan document allows exceptions, the plan often reverses.
Upheld citing utilization criteria. The plan cites its own medical policy or clinical guideline.
Approval for reduced frequency. The plan approves some but not all of the additional visits.
Recoded to medical necessity or non-covered. Sometimes the plan drops the frequency argument.
How to handle each outcome
Reversal: confirm reprocessing.
Upheld: request the plan's medical policy that was applied. File second-level appeal with a stronger letter of medical necessity that addresses the specific criteria the plan applied. External review works well here because a physician reviewer can evaluate clinical reasoning.
Partial approval: decide whether to accept or appeal the balance. Sometimes the plan's compromise is reasonable.
Recoded: demand the plan pick a lane.
Mental health parity
If CO-151 applies to a mental health or substance use disorder service, and the frequency limit is more restrictive than comparable medical/surgical frequency limits, that is a possible MHPAEA violation. Cite 42 USC 300gg-26 in the appeal.
Common exception arguments
- Acute exacerbation. The patient's condition worsened, requiring additional care beyond the initial course.
- Complex diagnosis. The condition is more complex than the plan's utilization criteria assume.
- Failure of alternatives. Other treatments were tried and did not work.
- Preventive necessity. The additional frequency prevents worse outcomes (readmission, complications).
- Regulatory requirement. Some conditions (chronic kidney disease, cancer) have federally-recognized care frequency standards that exceed the plan's general utilization criteria.
What to gather
- Your provider's chart notes for each of the visits at issue
- A letter of medical necessity from the treating physician
- The plan's medical policy (request it explicitly under 29 CFR 2560.503-1(g)(1)(v) for ERISA plans)
- Clinical practice guidelines from professional societies (APA, APTA, AAPM, and so on)
- Prior authorizations if any were obtained
Sample argument
"The plan denied additional [service] visits under CO-151, citing its policy limiting [service] to [number] visits per [period]. My provider has documented that my condition requires [number] additional visits because [clinical reasoning]. The plan document at [section] permits additional services when medically necessary. Attached is my provider's letter of medical necessity supporting the additional frequency, along with clinical guidelines from [professional society] supporting the recommended approach for my condition."
When to escalate
External review under ACA section 2719 is strong for CO-151 denials involving medical judgment. State DOI is the right escalation for CO-151 denials that appear to violate MHPAEA or that have a pattern of stonewalling.