391.49 — Driving without required medical waiver/exemption
49 CFR 391 • Driver Fitness BASIC • Severity 5/10
What this violation means
Driver with a condition that would normally disqualify (vision, diabetes, epilepsy) operating without the FMCSA waiver in possession. OOS.
Why this gets cited
Waiver expired. Waiver letter not carried.
How to fix / prevent
FMCSA waiver letter in cab. Track expiration date.
Out-of-service criteria
Yes — this violation IS out-of-service eligible. When an inspector finds 391.49 during a Level 1, 2, or 3 inspection, they can place the Driver OOS using the North American Standard Out-of-Service Criteria. OOS means the truck cannot move from the inspection site until the defect is corrected (vehicle OOS) or the driver is replaced (driver OOS). For carriers, every OOS violation adds time-weighted points to your CSA Driver Fitness BASIC — and it shows in the public SMS data within 30 days. For drivers, an OOS event stays on PSP for 3 years.
CSA / SMS impact
391.49 carries a severity weight of 5/10 in FMCSA's Safety Measurement System (SMS). Higher weights mean faster CSA percentile movement. Combined with a time-weighting factor (2× for citations within the last 6 months, decaying over 24 months), this violation can move your Driver Fitness BASIC percentile significantly if it stacks with similar citations across your fleet. The threshold for FMCSA intervention is the 65th percentile for most BASICs (50th for Hazmat and Passenger Carrier). Once you cross that, FMCSA can send a Warning Letter, Off-Site Investigation, or full Compliance Review.
How to read this: a single citation rarely puts you over threshold — it's the pattern. Track your inspection rate per power unit and aim for OOS rate under 5% (industry average is 21%).