How NPPES update dates should be interpreted

Several dates can appear on a ProviderFront profile, and they should not be collapsed into one “new” date.

• Enumeration date comes from the public record and describes when the NPI was assigned.
• Last official update is the NPPES record’s update date.
• First seen is the first complete ProviderFront batch that contained the record.
• Last checked is the latest complete batch used for the displayed profile.
• Signal detected is when ProviderFront identified a deterministic difference between valid snapshots.

An old NPI can have a recent official update. A newly observed record can have an old enumeration date if it entered ProviderFront’s history later. A weekly source batch can also be processed after the underlying official update date.

ProviderFront builds changes only after a complete batch passes validation, so partially downloaded or quarantined data cannot produce public signals. Alerts and exports retain the supporting dates to prevent the timeline from losing context downstream.