Why was my MCS-150 rejected by FMCSA?
The two most common rejection causes are USDOT-and-name mismatch (the legal name on the form doesn't match the FMCSA record) and missing/inconsistent required fields (mileage, vehicle counts, classification). FMCSA validates the form at submission and surfaces specific rejection reasons via the portal or email.
A USDOT-and-name mismatch typically occurs when the carrier has gone through a DBA change, ownership change, or LLC restructuring without updating the FMCSA record. The MCS-150 has to match exactly what FMCSA has on file — even a missing comma or a "LLC" vs "L.L.C." discrepancy can cause a rejection.
Missing required fields most often hit the mileage estimate and the driver counts. Both fields are required on every filing. The mileage figure should reflect annual highway miles (not lifetime miles); driver counts should reflect actual full-time + part-time + casual drivers, not just full-time staff.
Inconsistent fields can also trigger rejection — a carrier reporting 1 power unit but 50 trailers, or 0 mileage with 5 power units, fails internal sanity checks. The form's logic does not allow obviously inconsistent inputs.
Less common: filing under an EIN that has been retired or a USDOT that has been deactivated for an extended period. These typically need a phone call to FMCSA to clear before refiling. The fix in most cases is straightforward — correct the offending field and resubmit. There is no FMCSA fee for the resubmission.