What should be entered in Block 24 J?

Block 24 J on the CMS-1500 form is specifically designated for the rendering provider's National Provider Identifier (NPI). This is critical as the NPI is a unique identification number for healthcare providers in the United States that is used to process claims and facilitate payments and transactions in the healthcare system.

Including the NPI in Block 24 J ensures that the insurance company correctly identifies the healthcare provider who rendered the services, streamlining the claims processing workflow. This is important for compliance with the HIPAA regulations that require the use of NPIs for healthcare providers.

The other choices do not belong in this block because additional information, such as the provider's contact number, the patient's identification number, or the provider's license number, is either irrelevant for this specific section or is recorded in different parts of the form. This reinforces the need for accuracy in how Block 24 J is completed to prevent issues with claim processing.