Skip to main content

MA37 Remark Code: Missing or Invalid Patient Address

MA37 means the patient's address on the claim is missing, incomplete, or invalid. The payer requires a complete, valid address for the patient, and could not accept the one reported.

Quick facts

Code
MA37 (RARC MA37)
Status
Active In use since January 1, 1997; last modified February 28, 2003.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The provider needs to fix the address field. The patient is not billed for a claim returned on this basis.
Official description
Missing/incomplete/invalid patient's address.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What MA37 means

Payers use the patient’s address to identify the member, send explanations of benefits, and sometimes determine pricing or coverage rules by location. MA37 says the address you sent was missing or failed validation.

It usually arrives with CARC 16 and is quickly fixed once the correct address is on the claim.

Common causes

  • Registration left the street line, city, or ZIP code blank.
  • An invalid ZIP code or a ZIP that does not belong to the state entered.
  • A temporary or outdated address that the payer cannot validate.
  • Address text exceeding field limits and getting truncated.
  • When the patient is the insured, the address was entered only in the insured fields.

How to fix it

  1. Confirm the current address with the patient or the eligibility response.
  2. Correct box 5 or the institutional equivalent, making sure every component is complete.
  3. Resubmit the corrected claim, following payer rules for replacement claims if the original was processed.

How to prevent it

Use address validation in your registration system and ask patients to confirm their address at each visit. Most address problems can be caught automatically before billing with a Claims Validator.

Codes that may appear with MA37

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim is missing information required for adjudication, and MA37 names the patient address.
  • MA36 (Missing/incomplete/invalid patient name.): The patient name is missing or invalid.
  • MA48 (Missing/incomplete/invalid name or address of responsible party or primary payer.): The name or address of the responsible party or primary payer is missing or invalid.
  • MA60 (Missing/incomplete/invalid patient relationship to insured.): The patient's relationship to the insured is missing or invalid.

MA37 FAQ

Where does the patient address go?

Box 5 on the CMS-1500 and form locator 9 on the UB-04. Electronic claims carry it in the patient or subscriber address segments.

Can I use a P.O. box?

For the patient's address, many payers accept a mailing address, but rules differ. The billing provider address, by contrast, often must be a physical location.

What counts as incomplete?

Typically a missing street line, city, state, or ZIP code, or a ZIP code that does not match the state.