I agree, the provider billing should never be submitted using the same NPI under rendering provider. Each provider must be individually credentialed and each must possess a unique NPI. The provider rendering the service is the NPI that must be submitted on the claim as the rendering provider. If the provider is a non credentialed NP or PA and if the service has met the requirements for incident-to service, then the provider that is in the office suite area at the time of the encounter will use their unique NPI as the supervising provider. The rendering/supervising NPI goes in field 24J of the claim. It cannot be the same NPI for all services rendered unless the same provider is rendering all services or is in the office supervising qualified personnel.