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MA40 Remark Code: Missing or Invalid Admission Date

MA40 means the admission date on the claim is missing, incomplete, or invalid. For inpatient and other admission-based claims, the payer needs a valid admission date to apply benefit period, payment, and timing rules.

Quick facts

Code
MA40 (RARC MA40)
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 facility must correct the claim. The patient should not be billed for a claim returned on a data error.
Official description
Missing/incomplete/invalid admission date.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What MA40 means

MA40 is an institutional claim edit. The admission date anchors an inpatient stay: it determines which benefit period the stay falls in, which payment rates apply, and whether related services, such as those in the days before admission, are bundled. MA40 says that date was missing or could not be accepted.

A valid admission date must be a real date, must not be after the statement period’s from date, and must be consistent across interim and final claims for the same stay.

Common causes

  • The admission date was left blank on an inpatient claim.
  • The admission date falls after the statement from date.
  • Interim claims for the same stay carry different admission dates.
  • The observation start date was entered instead of the inpatient order date.

How to fix it

  1. Confirm the admission date from the inpatient order and the patient’s account.
  2. Correct form locator 12 and check it against the statement period in form locator 6.
  3. Align all claims for the stay so interim and final claims share the same admission date.
  4. Resubmit the corrected claim using the replacement frequency code if needed.

How to prevent it

Pull the admission date directly from the registration record rather than re-entering it on the claim, and review status changes from observation to inpatient carefully. Header errors like this are covered in claim rejection vs. denial.

Codes that may appear with MA40

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Claim information is missing or invalid, with MA40 pointing to the admission date.
  • MA31 (Missing/incomplete/invalid beginning and ending dates of the period billed.): The statement period dates are missing or invalid.
  • MA41 (Missing/incomplete/invalid admission type.): The admission type is missing or invalid.
  • MA42 (Missing/incomplete/invalid admission source.): The admission source is missing or invalid.

MA40 FAQ

Where is the admission date reported?

Form locator 12 on the UB-04, along with the admission hour in form locator 13. On an 837I it is reported as the admission date and time at claim level.

Can the admission date be before the statement period?

Yes, on interim or continuing claims the admission date can precede the from date. It should never be after the from date.

Is an admission date needed on outpatient claims?

Usually not, but some bill types, such as certain home health or hospice claims, have their own start-of-care or admission date rules.