The MCS-150, or Motor Carrier Identification Report, is a form filed to obtain and update your USDOT number. The form contains a company’s information that the FMCSA uses and needs throughout the lifetime of the company.  It contains information such as company contact information, what type of carrier you are (intrastate or interstate), what type of goods hauled, mileage for a year along with the number of drivers and power units.