MA37 remark code

Remittance advice remark code MA37. Remark codes add detail to the reason code on the same claim line.

Missing or invalid patient address

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 MA37 means

The patient's address on the claim is missing, incomplete or not valid.

The payer needs a usable patient address, often for pricing by location or for program rules tied to where the patient lives. This remark says the address was missing or could not be used.

It usually comes with reason code 16. Check the ZIP code in particular, since it often drives location based pricing.

Common causes

• The address was blank or missing the ZIP code.
• A post office box or incomplete street address was used where a residence address was needed.
• The address had not been updated after the patient moved.

What to do next

1. Confirm the patient's current address at registration or by phone.
2. Update the patient record with a full address including ZIP code.
3. Send a corrected claim with the full, current patient address.

Related codes

• 16 (reason code) Missing information or billing error
• MA36 (remark code) Missing or invalid patient name
• M115 (remark code) Item needs a contract supplier