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M52 Remark Code: 'From' Date of Service Invalid

M52 means the payer could not accept the 'from' date of service on the claim or line. The start date was missing, incomplete, or invalid, so the payer could not tell when the service began.

Quick facts

Code
M52 (RARC M52)
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 line is unpaid until a valid start date is supplied. It is a provider data issue.
Official description
Missing/incomplete/invalid 'from' date(s) of service.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What M52 means

Every service line needs a date, and for spans of service (such as monthly rentals or a series of treatments) that date has two parts: a start and an end. M52 is about the start. The payer found the ‘from’ date blank, in the wrong format, logically impossible, or inconsistent with other claim information.

It is usually seen with CARC 16, and many payers return such claims as unprocessable.

Common causes

  • Typos, such as a transposed month and day or a wrong year.
  • A future date or a date before the patient’s coverage or birth date.
  • A ‘from’ date later than the ‘to’ date on the same line.
  • Line dates falling outside the claim’s statement period on an institutional claim.
  • Date formats changed during conversion by a clearinghouse.

How to fix it

  1. Check the service line against the medical record to confirm when the service started.
  2. Correct box 24A (or the institutional line service date) with a valid date in the payer’s format.
  3. Make sure the ‘from’ date is not after the ‘to’ date and falls within any statement period.
  4. Resubmit. Use a new claim if the payer returned it unprocessed, or resubmission code 7 for a processed claim.

How to prevent it

Add date-logic edits in your billing system: no future dates, start before end, and dates within coverage. A Claims Validator check catches these before submission. See claim rejection vs denial for how returned claims are handled.

Codes that may appear with M52

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim lacks information or has billing errors, here the start date.
  • CO-A1 (Claim/Service denied.): Some payers deny the whole claim when the service dates are unusable.
  • M59 (Missing/incomplete/invalid 'to' date(s) of service.): The ending ('to') date is the problem instead of the start date.
  • MA31 (Missing/incomplete/invalid beginning and ending dates of the period billed.): The beginning and ending dates of the whole billing period are missing or invalid.
  • N301 (Missing/incomplete/invalid procedure date(s).): The procedure date, as opposed to the service line date, is missing or invalid.

M52 FAQ

Where is the 'from' date on the CMS-1500?

In box 24A, the 'From' column for each service line. For a single-day service, the 'To' date is the same or left blank per payer rules.

Can a future date trigger M52?

Yes. A date after the claim receipt date, or an impossible date such as February 30, is considered invalid.

Does M52 affect timely filing?

The timely filing clock runs from the actual date of service, so correct and resubmit promptly.