The CDC described the core functionality of a population-based immunization registry as follows:

1. Consolidate all immunization records from multiple providers.
2. Electronically store data on all NVAC-approved core data elements.
3. Link electronically with birth data to automatically populate the registry.
4. Permit providers to electronically retrieve information on all immunizations records at the time of the encounter.
5. Ensure accurate and complete immunization records through automated de-duplication and edit checking.
6. Protect confidential medical information (security).
7. Recover lost data.
8. Exchange immunization records using HL7 standards.
9. Automatically determine the immunization(s) needed when an individual presents for a vaccination based on current ACIP recommendations.
10. Provide authorized immunization records.
11. Identify individuals late for immunization and produce recall notifications.
12. Permit providers to electronically submit information on all immunization encounters on the same day as vaccine administration
13. Enable identification and flagging of the definitive record.
14. Automatically produce CASA-like immunization coverage reports by provider.