Glossary · updated October 31, 2026
Biennial Update
Also known as: MCS-150 Biennial Update, 24-Month Update, 24-Month Cycle, Biennial Cycle
By Korey Sharp-Paar · Reviewed by the Fast Trucking Compliance team
Definition
The biennial update is the MCS-150 refresh FMCSA requires of every USDOT number holder every 24 months, even when nothing has changed. "Biennial" means once every two years. The month and year are set by the USDOT number, not by the registration anniversary: the last digit sets the month (1 = January through 9 = September, 0 = October), the next-to-last digit sets odd or even years, and the update is due by the last day of that month (49 CFR 390.19T). An early or out-of-cycle update does not reset the clock. A missed biennial update can lead to civil penalties and deactivation of the USDOT number (49 CFR 390.19T(b)(4)). FMCSA has temporarily suspended enforcement and USDOT inactivation for biennial updates due on or after June 1, 2026; the update is still required.
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MCS-150 Filing Schedule: When Is Your Biennial Update Due?Your MCS-150 due month and year are set by your USDOT number. Learn the exact FMCSA schedule so you never miss a biennial update deadline.
Related terms
- MCS-150(Motor Carrier Identification Report)
- Last-Digit Filing-Month Rule(Last Digit Month Rule)
- Next-to-Last-Digit Year Rule(Even/Odd Year Rule)
- USDOT Deactivation(Deactivation)