HCFA-1500 Box 24j - Rendering Provider ID

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August 25, 2025

On the HCFA-1500 form, Box 24J is used to report the Rendering Provider Identification. This is most commonly the provider’s National Provider Identifier (NPI), which is required for HIPAA-compliant electronic claims. In some cases, payers may also request a secondary (legacy) ID, such as a Medicaid provider number or commercial identifier.

Tip: Always enter the NPI in Box 24J when required. Only include a legacy ID if the payer specifically requests it. Most modern billing requires only the NPI.

In our example below, the provider reported a legacy ID of TR1234 and an NPI of 1234567893.

HCFA-1500 Box 24J - Rendering Provider ID

In the X12 837P 5010 transaction, Box 24J maps to the Rendering Provider Identification in one of two places:

  • 2310B NM109 – Rendering Provider Identifier (claim-level NPI)
  • 2420A NM109 – Rendering Provider Identifier (service line–level NPI)
  • 2310B REF02 – Rendering Provider Secondary Identification (claim-level legacy ID)
  • 2420A REF02 – Rendering Provider Secondary Identification (service line–level legacy ID)

Sample 837P (5010) – Box 24J Mapping

> Rendering Provider NPI (2310B – Claim Level) NM1*82*1*DOE*JOHN****XX*1234567893~ > Rendering Provider Secondary ID (2310B – Claim Level) REF*G2*TR1234~

Segment Breakdown:

  • NM109: Provider NPI (required in most claims)
  • REF01: Qualifier identifying the legacy ID type (e.g., G2 = Provider Commercial Number)
  • REF02: The actual secondary identification number (e.g., TR1234)

Note: Most payers only require the NPI in Box 24J. Include a legacy ID only if specifically instructed by the payer. Both claim-level (2310B) and service line–level (2420A) reporting are supported, but the NPI is always the primary identifier.

For additional information on the X12 837 standard, please refer to the official implementation guides published by X12.

HCFA-1500 Form Box Locations

Grab a sample of the HCFA-1500 claim form here - HCFA 02/12 Claim Form


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