What is an Out of Service order?
An out-of-service (OOS) order is an enforcement action that stops a specific vehicle, driver, or carrier from operating until the problem is corrected. A vehicle OOS lasts until the defect is repaired, a driver OOS until the driver is back in compliance (for example, after enough off-duty time for an hours-of-service violation), and a carrier-level OOS until FMCSA rescinds the order.
Vehicle-level OOS: a roadside inspector finds a defect covered by the out-of-service criteria (for example, a critical brake or mechanical defect), and the vehicle can't be operated until the repair is made.
Driver-level OOS targets the individual driver: hours-of-service violations, disqualification under 49 CFR 391.15, or licensing issues. An hours-of-service OOS lasts until the driver has enough off-duty time to be back in compliance; a disqualification lasts for the period the regulations set.
Carrier-level OOS is the most severe. It can follow an Unsatisfactory safety rating becoming final (49 CFR 385.13), a failed new-entrant audit (49 CFR 385.325), an imminent-hazard finding, or unpaid civil penalties (49 CFR 386.83), and it stops the whole operation until FMCSA rescinds the order. Once the underlying cause is resolved, your reinstatement is submitted to FMCSA promptly; FMCSA controls the timing.
Operating while under an out-of-service order is a separate violation subject to civil penalties under 49 CFR Part 386. Brokers, shippers, and roadside inspectors can see OOS status in FMCSA's records.