The schedule is unchanged
The Motor Carrier Identification Report (MCS-150) biennial filing schedule under 49 CFR §390.19T is unchanged in 2026. The MONTH is determined by the LAST digit of your USDOT number; the YEAR is determined by the SECOND-to-last digit (even or odd). A USDOT ending in ...23 files in March of every odd year; one ending in ...40 files in October of every even year.
Missing the deadline triggers immediate USDOT deactivation under 49 USC §14901. Reactivation is free but blocks loads in the meantime.
New portal interface
FMCSA refreshed the MCS-150 web portal in February 2026 to consolidate MCS-150 (basic carrier identification), MCS-150B (hazmat), and MCS-150C (intermodal equipment provider) on one update screen. Carriers operating in multiple categories no longer toggle between separate pages.
The portal also auto-flags fields that haven't changed since the last filing, so two-year updates only require attention to the cells that actually moved (power units, mileage, drivers, hazmat status). The full FMCSA portal is at safer.fmcsa.dot.gov.
Common MCS-150 errors
Carriers most often under-report drivers. The drivers field counts every CDL holder dispatched under the carrier's authority during the prior 12 months - including occasional contractors. Under-reporting can flag the carrier for compliance review.
The mileage field should match what you reported to IFTA for the same period. A 30%+ discrepancy between MCS-150 mileage and IFTA mileage triggers an FMCSA data integrity flag.