N850 remark code

Remittance advice remark code N850. Remark codes add detail to the reason code on the same claim line.

Service narrative missing or invalid

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 N850 means

The written description explaining the service or treatment was missing, incomplete or not usable.

Some claims need a short narrative in a claim note, for example to explain an unusual circumstance, a not otherwise classified item or why a modifier applies. N850 means that narrative was absent or did not give the payer what it needed.

It usually explains reason code 16. The payer normally expects a corrected claim with a clear narrative, sometimes with records.

Common causes

• The claim note field was left blank where the payer requires it.
• The note was cut off by a character limit or not transmitted.
• The narrative was too vague to explain the service.

What to do next

1. Check which claim field the payer reads for narratives on this claim type.
2. Write a short, specific description of the service and why it was needed.
3. Submit a corrected claim with the narrative included.
4. Attach supporting records if the payer's policy asks for them.

Related codes

• N350 (remark code) Unlisted code needs a description
• N706 (remark code) Documentation missing
• 16 (reason code) Missing information or billing error