Reference·X12 837P·CLM
X12 837P Reference

X12 837P CLM Explained: Structure, Fields, and Common Mistakes

Jul 27, 2026 · 6 min read

The CLM segment is where an 837P claim states what it actually is — original, correction, or void — and how much it's asking the payer to pay. Get the composite elements wrong and the claim either gets denied outright or silently mismatched to the wrong original claim.

Quick answer

CLM (Claim Information) is the core segment of an X12 837P professional claim — it carries the claim submitter's identifier, the total charge amount, and a composite of codes describing the facility, frequency, and provider signature status.

The elements that actually matter in practice

CLM01 →
Claim Submitter's Identifier — your internal claim/patient control number
CLM02 →
Monetary Amount — total claim charge amount
CLM05
Health Care Service Location Information — composite — facility code, qualifier, frequency code
CLM05-3 →
Claim Frequency Type Code — original / correction / void — see the dedicated field guide below
CLM06 →
Provider Signature Indicator — Y/N — whether a signature is on file
CLM08 →
Benefits Assignment Certification Indicator — Y/N/W — whether benefits are assigned to the provider
CLM09 →
Release of Information Code — authorization to release info for claim adjudication

Example

Synthetic example Generated by Synthibase 
CLM*ACCT88213*450.00***11:B:1*Y*A*Y*Y*P*

Composite 11:B:1 breaks down as facility code 11, frequency qualifier B, frequency code 1 (original claim). Synthetic claim data.

Where this trips people up

Submitting a correction (CLM05-3 = 7) without a matching REF*F8 segment carrying the original claim's payer control number is one of the most common 277CA rejections teams hit at go-live — the claim looks fine in isolation but the payer has no idea what it's correcting.

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What is X12 837P? Complete Format and Field Guide
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How to Reduce Claim Denials Through Better Pre-Submission Testing
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This page is written independently by Synthibase for testing and informational purposes. It is not an official publication of HL7 International or X12/Washington Publishing Company, and is not a substitute for reviewing the official standard or your trading partner's companion guide. See our Terms of Service for full legal terms.