Do I need to report to immigration at 90 days if I have an extension on my tourist visa in Thailand?

If you are on a tourist visa and have received an extension, you do not need to report to immigration at the 90-day mark as this requirement typically applies to other types of visas. Since tourist visas and their extensions are generally valid for up to 90 days, reporting is not necessary if you will be leaving Thailand before the 90-day period ends.