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N440 Remark Code: Invalid Anesthesia Physical Status

N440 means the anesthesia physical status report or indicator was incomplete or invalid. Physical status information was on the claim, but the payer could not accept it: for example, a P modifier on the wrong line, conflicting values, or a status that does not match the records.

Quick facts

Code
N440 (RARC N440)
Status
Active In use since July 1, 2008.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The anesthesia service needs valid physical status data to process. The provider fixes the information; the patient is not billed.
Official description
Incomplete/invalid anesthesia physical status report/indicators.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N440 means

With N440 the physical status indicator is there, but the payer rejected it as incomplete or invalid. The physical status classification is reported with modifiers P1 through P6, and payers edit those modifiers for placement, count, and consistency with the service. When the value fails those edits, the anesthesia line is returned with N440, usually beside CARC 16.

What makes a physical status value invalid

  • Wrong line. The P modifier was attached to a surgical or non-anesthesia code instead of the anesthesia code.
  • Conflicting modifiers. Two P modifiers on the same line, or different values on lines for the same anesthesia service.
  • Unsupported value. P6 billed for a patient who does not meet that definition, or a value that contradicts the anesthesia record.
  • Formatting problems. A modifier truncated or mistyped during entry, or placed where the payer’s system does not read it.
  • Report mismatch. The payer requires a physical status report and the report conflicts with the claim.

What to do

  1. Look at the anesthesia line on the claim and list every modifier, in order.
  2. Compare with the anesthesia record to confirm the documented physical status.
  3. Keep one correct P modifier on the anesthesia code and remove any from other lines.
  4. Check payer rules for modifier order and for any report requirement.
  5. Send a corrected claim with resubmission code 7 and the original claim number, and include a corrected report if the payer asked for one.

How to prevent it

Restrict P modifiers in your billing system so they can be added only to anesthesia codes, and allow only one per line. A pre-bill check comparing the billed physical status with the anesthesia record catches most mismatches. Claims Validator can also flag modifier conflicts before submission.

Codes that may appear with N440

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim contains an error; N440 says it is in the anesthesia physical status data.
  • CO-4 (The procedure code is inconsistent with the modifier used.): The procedure code is inconsistent with the modifier used, which can include a P modifier on a non-anesthesia code.
  • N439 (Missing anesthesia physical status report/indicators.): The physical status information is missing entirely.
  • N203 (Missing/incomplete/invalid anesthesia time/units.): Anesthesia time or units are missing, incomplete, or invalid.
  • CO-194 (Anesthesia performed by the operating physician, the assistant surgeon or the attending physician.): Anesthesia performed by the operating physician, assistant surgeon, or attending physician.

N440 FAQ

How is N440 different from N439?

N439 means the physical status was not reported. N440 means something was reported, but it was incomplete, invalid, or inconsistent.

Can a claim have more than one P modifier?

An anesthesia line should normally carry one physical status modifier. Two different P modifiers on the same line conflict and are a likely cause of N440.

Does the payer check physical status against the record?

It can, especially if it pays additional units for higher physical status or reviews the claim. The billed value should match what the anesthesia provider documented.