Reference
X12 adjustment group codes
The group code on every line of your EOB tells you who is responsible for the adjustment. There are exactly four: CO, PR, OA, PI. Together with the CARC reason code, they explain the ‘why’ and the ‘who’ of every adjustment.
Total group codes
4
Source
X12 / WPC
Group code CO
Contractual Obligation
Contractual write-off. The provider agreed to the rate. Patient does NOT owe this amount.
Group code PR
Patient Responsibility
Patient owes this amount. Deductibles, coinsurance, copays, and excluded benefits land here.
Group code OA
Other Adjustment
Informational or coordination-related adjustment. Usually means another payer is involved or there's a non-claim-related accounting entry.
Group code PI
Payer Initiated Reductions
Payer reduced the payment for a reason that is neither contractual nor patient responsibility. Often appealable.
Sources
Contact: hello@denialhelp.com