CO-148 denial code
Information from another provider was not provided or was insufficient
How to fix it
Identify what was needed and obtain it from the other provider, then resubmit.
How to prevent it
Where you depend on outside documentation, request it before submitting rather than after denial.
In practice
A laboratory bills a test that requires the ordering physician's supporting diagnosis and clinical indication. The physician's office never responded to the payer's request, and the claim returns CO-148.
The information the payer needed was somebody else's to supply, and the billing provider absorbs the denial. That structural unfairness is the defining feature of this code.
Obtaining the information directly from the other provider and submitting it yourself is usually faster than waiting for them to respond to the payer. Referencing the claim number and the specific request makes it far more likely to be processed on arrival.
What sits behind it
Providers who depend on outside documentation carry this exposure continuously — laboratories, imaging centres, equipment suppliers, home health agencies and anaesthesia groups all bill for work initiated elsewhere and all rely on records they do not control.
The workable defence is collecting what will be needed at the point of order rather than at the point of denial. A requisition that captures the indication, the ordering provider's identifier and the supporting diagnosis at intake removes most of these before they can happen.
Where one referral source generates these repeatedly, the conversation belongs with that practice rather than with the payer. A short discussion about what their orders need to carry resolves more than months of individual claim chasing.
Related codes
Terms used here — Medical Necessity · Denial · Minimum Necessary
How we handle it — Denial Management · Claims Management · AR Management
Primary sources
The rules behind CO-148, at the bodies that publish them.
- Evaluation and Management services guide (opens in a new tab)
Centers for Medicare & Medicaid Services — How E/M level is determined under the current medical decision making and time rules. The reference for any dispute about whether documentation supports a level.
- Medicare Claims Processing Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — The operative manual for how Medicare claims must be coded, submitted, adjusted and appealed. When a payer policy and a vendor's advice disagree, this settles it.
- Medicare claims appeals process (opens in a new tab)
Centers for Medicare & Medicaid Services — The five levels of appeal, what each requires and the deadline for each. Missing a level's deadline ends the appeal regardless of the claim's merits.
Looking for a different code? Search all 190 CARC and RARC codes
Questions about CO-148
Usually yes, and it is generally faster. Obtain the record from the ordering practice and submit it directly, referencing the claim number and the specific request. Waiting for another office to respond to a payer request rarely produces a timely result.
By capturing what the payer will need on the requisition itself — the clinical indication, the ordering provider's identifier and the supporting diagnosis. Collecting it when the order arrives removes the dependency that produces the denial weeks later.
Address it with that practice rather than through the payer. A brief conversation about what their orders should carry resolves the pattern, whereas chasing each claim individually treats the symptom and leaves the source unchanged.
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