CO P30 denial code

Claim adjustment reason code P30. Often reported as CO P30.

Flare up denied: incomplete records

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 Nov 11, 2026.

What P30 means

On a property and casualty claim, care billed for a flare up of the condition was denied because supporting records were incomplete.

It belongs to property and casualty billing, such as workers' compensation or auto medical claims. An exacerbation is a worsening of an existing injury. Payers usually require documentation that shows the flare up, its link to the original injury and the treatment needed.

P30 means the payer did not get enough of that support. Complete records often reverse the denial.

Group codes seen with P30

On a remittance, P30 comes after a group code. These are the ones it is most often reported with:

• CO P30 (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

• The notes did not describe the worsening or its link to the original injury.
• Required forms for exacerbation care were not filed.
• The records submitted were incomplete.

What to do next

1. Gather the notes that describe the exacerbation and its cause.
2. Submit the complete documentation with a request for reconsideration.
3. Check the payer's requirements for exacerbation care before future visits.

Related codes

• P31 (reason code) Exacerbation denied: time limit exceeded
• P15 (reason code) Outside workers' comp treatment guidelines