From USAC:
Event Promoters
* Agree to submit race results in the 21 days following the conclusion of the event.
* Recognize that should a promoter not live up to this agreement, action may be taken by USAC on future sanctioning of events.
So, it's required and I see a lot of poor
excuses for it not being done, but I'm still curious why it's so pervasive. All the trouble everyone goes through and at the end to miss the boat with one simple thing. After all, racing is about results.