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.
A missed biennial update can lead to civil penalties and deactivation of your USDOT number (49 CFR 390.19T(b)(4)). Note: FMCSA has temporarily suspended enforcement of biennial updates and USDOT inactivation for updates due on or after June 1, 2026, until further notice. The update is still required.
Source: 49 CFR 390.19T (eCFR): https://www.ecfr.gov/current/title-49/subtitle-B/chapter-III/subchapter-B/part-390/subpart-B/section-390.19T
Source: FMCSA, Temporary Suspension of the Biennial Update Requirement: https://www.fmcsa.dot.gov/registration/temporary-suspension-biennial-update-requirement
Common MCS-150 errors
A common error is under-reporting drivers. The MCS-150 instructions ask for the number of interstate and intrastate drivers operating CMVs on an average workday, counting part-time, casual, term-leased, trip-leased, and company drivers.
Report vehicle mileage for the period the form asks for and keep the supporting records; your IFTA mileage records are a useful cross-check.