MA61 remark code

Remittance advice remark code MA61. Remark codes add detail to the reason code on the same claim line.

Missing or invalid Social Security number

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 MA61 means

The Social Security number on the claim is missing, incomplete or not valid where the payer requires it.

Some payers and claim situations still require a Social Security number. This remark says the number was blank, the wrong length, or did not match the payer's records.

It usually comes with reason code 16. Be careful with how this number is stored and sent, since it is sensitive data.

Common causes

• The field was left blank where the payer requires it.
• The number was keyed with a typo or the wrong number of digits.
• The subscriber's number was entered where the patient's was needed, or the reverse.

What to do next

1. Confirm whether the payer actually requires the number for this claim.
2. Verify the number with the patient and correct the record.
3. Send a corrected claim, and store the number only where it is needed.

Related codes

• MA27 (remark code) Missing or invalid entitlement ID or name
• MA36 (remark code) Missing or invalid patient name
• 16 (reason code) Missing information or billing error