N122 remark code

Remittance advice remark code N122. Remark codes add detail to the reason code on the same claim line.

Add-on code billed alone

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 N122 means

An add-on code was billed without the primary procedure it must accompany, so it cannot be paid by itself.

Add-on codes describe extra work done on top of a primary procedure and are never paid on their own. N122 means the payer did not find the required primary code on the same claim or for the same provider and date.

It typically supports a reason code such as 107 or 4. Fixing the primary code usually gets the add-on paid.

Common causes

• The primary procedure was billed on a separate claim or by a different provider.
• The primary code was denied, so the add-on lost its anchor.
• The add-on was paired with a primary code that is not on its list of allowed primary codes.

What to do next

1. Check that the primary procedure appears on the same claim with the same date and rendering provider.
2. Review the add-on code's list of allowed primary codes.
3. Resolve any denial on the primary code first, then request reprocessing of the add-on.
4. Send a corrected claim that bills the primary and add-on together.

Related codes

• N657 (remark code) Bill with the right code
• N20 (remark code) Not payable with same-day service
• 4 (reason code) Procedure code and modifier do not match