N846 remark code

Remittance advice remark code N846. Remark codes add detail to the reason code on the same claim line.

NDC does not match the code

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 N846 means

The National Drug Code on the line does not belong with the HCPCS or CPT code billed for the drug.

Many payers require the NDC of the drug given along with the procedure code. N846 means the payer checked the two against each other and found they do not correspond, so it cannot price or verify the drug.

It usually supports reason code 16 or 4 and is fixed by sending the correct pairing.

Common causes

• The NDC on the claim belongs to a different drug or strength than the code describes.
• The NDC from a different vial or package size was used and is not mapped to the code.
• The NDC or code was entered with a typo or in the wrong format.

What to do next

1. Check the NDC on the vial or invoice against the procedure code billed.
2. Confirm the NDC is in the right format with any leading zeros.
3. Submit a corrected claim with the matching NDC and code.
4. Update the pharmacy or charge master crosswalk for that drug.

Related codes

• N350 (remark code) Unlisted code needs a description
• N657 (remark code) Bill with the right code
• 16 (reason code) Missing information or billing error