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All interstate commercial motor vehicles (private, for-hire, and exempt) who meet the definition of commercial motor vehicle found in 390.5 must submit the online Form MCSA-1 and obtain a USDOT number before beginning operations. The commercial motor vehicle definition includes a vehicle which:
(1) Has a gross vehicle weight rating or gross combination weight rating, or gross vehicle weight or gross combination weight, of 4,536 kg (10,001 pounds) or more, whichever is greater; or
(2) Is designed or used to transport more than 8 passengers (including the driver) for compensation; or
(3) Is designed or used to transport more than 15 passengers, including the driver, and is not used to transport passengers for compensation; or
(4) Is used in transporting material found by the Secretary of Transportation to be hazardous under 49 U.S.C. 5103 and transported in a quantity requiring placarding.
Some states require USDOT numbers for intrastate carriers.