CO 150 denial code

Claim adjustment reason code 150. Often reported as CO 150.

Records do not support level of service

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 150 means

The payer decided the documentation does not justify the level of service billed, so payment was reduced or denied.

The payer reviewed what it had on file and concluded the service was billed at a higher level than the records support. This is common with visit levels and other services that come in tiers.

The payer may pay at a lower level or deny the line. Look at the documentation honestly: if it does support the level, appeal with the records; if not, correct the code.

Group codes seen with 150

On a remittance, 150 comes after a group code. These are the ones it is most often reported with:

• CO 150 (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 visit was billed at a high level and the note did not show the required complexity or time.
• The documentation sent did not include the parts of the record that support the level.
• The payer's review criteria differ from how the service was coded.

What to do next

1. Pull the record and compare it with the requirements for the level billed.
2. If the record supports the level, send an appeal with the full documentation.
3. If it does not, send a corrected claim at the level the documentation supports.
4. Share the finding with the provider and coder so future claims are coded to the record.

Related codes

• 151 (reason code) Records do not support number or frequency
• 152 (reason code) Records do not support length of service
• 50 (reason code) Not medically necessary per the payer