When is an N-400 (Application for Naturalization Form) considered approved or denied when the USCIS computes the processing time?

Question

The USCIS publishes processing times for the N-400 Application for Naturalization Form (mirror).

https://egov.uscis.gov/processing-times/more-info says:

Processing time is the number of months that elapse between the date we receive an application, petition, or request and the date we complete the application, petition, or request (that is, when we approved or denied it) for all cases for a specific form for the latest completed 6 months.

When is an N400 considered approved or denied when the USCIS computes the processing time? Is it when the letter notifying the interview appointment is sent? When the interview takes place? When the oath takes place? Some other time?

Answer 1

It is approved when "Notice of Approval" is sent. Generally this is done when all the conditions are met.

There may be multiple steps before an application is approved, some may include in-person interviews, others may include RFEs in writing, before the decision is given.

N400 applications may be denied even after approval, any time up to the naturalization ceremony, if the USCIS determines that the conditions are no longer met by the time of the ceremony (usually it means that either facts changed between the approval and the ceremony or the USCIS learned that the applicant misrepresented facts).