The FAA recommends requesting a PAPR after:

• A new ADS-B installation
• Replacing or repairing a transponder
• Installing or updating a GPS position source
• Software or configuration changes
• Annual inspections or troubleshooting
• Any maintenance affecting the aircraft's avionics

Many operators also request a report periodically simply to confirm continued compliance.

For more information:

https://adsbperformance.faa.gov/PAPRRequest.aspx