What type of national provider identifier (NPI) is required in Block 33a of a CMS-1500 claim form?

In Block 33a of a CMS-1500 claim form, the national provider identifier (NPI) that is required is the billing provider's NPI. The billing provider is the entity or individual who submits a claim for payment. This is a crucial aspect of the claims processing system, as it allows payers to identify who is billing for services rendered, which can include a private practice physician, a healthcare organization, or any other entity that provides care and is billing for it.

When accurate information is provided in Block 33a, it ensures that the claim can be processed correctly and reimbursed to the appropriate provider. The distinction of billing provider in this context is important, as it may not always coincide with the rendering provider (the individual who performed the service) or the group provider (a collective entity). By requiring the billing provider's NPI specifically, the CMS-1500 form facilitates clear communication and proper claims management in the healthcare billing system.