Reference·CLM Segment·CLM07
X12 837P Reference

What Is X12 837P CLM07? Assignment or Plan Participation Code, Explained for Testers

Jul 27, 2026 · 4 min read
← CLM06 CLM08 →

Send CLM07 = B (assignment not accepted) on a claim from an in-network provider and the payer's remittance logic may try to pay the patient directly instead of the practice — the kind of mismatch that only shows up once real money starts moving.

Quick answer

CLM07 is the Assignment or Plan Participation Code in an X12 837P claim — it states whether the billing provider accepts assignment of benefits or participates in the patient's health plan.

Valid code values

A
Assigned — provider accepts assignment — payer reimburses the provider directly
B
Assignment Accepted on Clinical Lab Services Only — narrow assignment limited to lab charges
C
Not Assigned — payer reimburses the patient, not the provider

Example

Synthetic example Generated by Synthibase
CLM*ACCT48120*340.25***11:B:1*Y*A*Y*Y*P*

The A immediately after CLM06 is CLM07, indicating the provider accepts assignment of benefits. Synthetic claim data.

Where this trips people up

CLM07 and CLM08 (benefits assignment certification) are conceptually similar but not interchangeable — test generators that copy one value into both fields produce claims that look internally inconsistent to payer adjudication logic even though each field individually validates against its own code list.

X12 837P CLM Explained: Structure, Fields, and Common Mistakes
What is X12 837P? Complete Format and Field Guide
How to Reduce Claim Denials Through Better Pre-Submission Testing
Generate claims that vary assignment scenarios correctly
Synthibase generates synthetic 837P claims with CLM07 and CLM08 populated independently and consistently, matching real-world assignment-of-benefits scenarios.
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