Final answer:
The HIPAA Identifier Rule requires all covered entities dealing with ePHI to use a standardized National Provider Identifier (NPI) to improve the efficiency and privacy of health information transmission.
Step-by-step explanation:
The HIPAA Identifier Rule mandates that all covered entities storing or transmitting ePHI must have a standardized number, known as the National Provider Identifier (NPI). This unique identifier is used across the healthcare system to improve the efficiency and effectiveness of the electronic transmission of health information.
Covered Entities, including health plans, healthcare clearinghouses, and certain healthcare providers, must use NPIs to identify themselves in standard transactions. By establishing a standardized identifier for health care providers, the HIPAA Identifier Rule helps to protect patient privacy by ensuring that entities are correctly and consistently identified in electronic transactions.