49 C.F.R. § 195.54

(a) Each operator that experiences an accident that is required to be reported under § 195.50 must, as soon as practicable, but not later than 30 days after discovery of the accident, file an accident report on DOT Form 7000-1 or 7000-2, whichever is applicable.

(b) Whenever an operator receives any changes in the information reported or additions to the original report on DOT Form 7000-1 or 7000-2, whichever is applicable, it shall file a supplemental report within 30 days.