CO 70 denial code
Claim adjustment reason code 70. Often reported as CO 70.
Cost outlier adjustment
Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated .
What 70 means
An inpatient claim was adjusted because its costs were high enough to qualify for extra outlier payment.
When a hospital stay is far more expensive than the typical case in its payment group, many payers add a cost outlier payment on top of the base rate. This code shows that adjustment amount on the remittance.
It is a pricing line, not a denial. The amount depends on the charges, the payer's cost-to-charge ratio and the threshold in the contract, so differences usually come down to those inputs.
Group codes seen with 70
On a remittance, 70 comes after a group code. These are the ones it is most often reported with:
- CO 70 (Contractual Obligation): The provider's side of the ledger. The reduction comes from the payer contract or a rule the provider has to follow, and the patient normally cannot be billed for it.
The payer chooses the group code for each adjustment, so the same reason code can appear with another group code on your remittance. Read the two together. More about group codes.
Common causes
- Total charges for the stay exceeded the payer's outlier threshold for the DRG or case rate.
- The payer applied its own cost-to-charge ratio or threshold when pricing the claim.
- Charges were later reduced or denied at line level, which changed the outlier result.
What to do next
- Recalculate the expected outlier using the contract formula and compare it with the remittance amount.
- Check whether any denied lines were excluded from the charges used in the outlier calculation.
- Send a pricing reconsideration with your calculation if the payer's figure is lower than the contract supports.
Related codes
Source
Official wording: X12 Claim Adjustment Reason Codes list. The explanation on this page is our own plain-English wording, not the X12 text.
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