What 391.45B means in plain language
FSMCR 391.45B addresses one of the foundational driver qualification requirements: maintaining a current medical examiner's certificate. As a commercial truck driver, you must pass a Department of Transportation (DOT) medical examination performed by an approved medical examiner and keep that certificate valid throughout your employment and operation.
When your medical certificate expires, you are no longer in compliance with federal safety requirements for driver fitness. This isn't a minor paperwork issue—it's a direct violation of the requirement that you demonstrate medical fitness to operate a commercial motor vehicle. The violation occurs the moment your certificate passes its expiration date, whether or not you're actually operating a truck at that moment.
What our enforcement data actually shows
Across our 13 million+ inspection records, 391.45B ranks #564 of 3,036 FMCSR codes by citation volume. Over the all-time record, we see 1,782 citations for this violation. In the last 12 months, enforcement officers cited 391.45B 529 times, with 48 citations logged in the last 90 days.
The out-of-service rate for 391.45B is notably low: 15.9% of all citations resulted in the driver being placed out of service. This is significantly below the all-FMCSR average OOS rate of 31.4%, reflecting the fact that many 391.45B violations are handled as warnings, correctable defects, or citations where the driver's certificate is renewed on-scene or shortly thereafter. Of the 1,782 all-time citations, 283 resulted in out-of-service placement while 1,499 did not.
The enforcement trend over the past 12 months shows volatility. May 2025 was the peak month with 162 citations and 52 out-of-service placements. Since then, monthly citation volume has declined steadily, with March 2026 logging only 19 citations.
Who gets cited most
Our inspection records show 391.45B citations are concentrated in a few states. North Carolina leads with 51 citations over the last 180 days, followed by Illinois with 25 citations and New Mexico with 14 citations.
The variation in OOS rates across these states is striking. Illinois shows an 80.0% out-of-service rate (20 OOS placements out of 25 citations), whereas North Carolina's rate is 39.2% (20 OOS out of 51 citations), and New Mexico's is 0.0% (no OOS placements across 14 citations). This 80-percentage-point spread between Illinois and New Mexico suggests different enforcement postures or circumstances across states—possibly reflecting stricter scrutiny in Illinois or different patterns of violation severity.
Top carriers cited for 391.45B include WEST TEXAS TRUCK SOLUTION LLC (USDOT 4287116) with 5 all-time citations and GARZA SAND & CONSTRUCTION LLC (USDOT 3328440) with 4 citations. These numbers are small in absolute terms, reflecting that 391.45B violations are widely distributed across the carrier universe rather than concentrated in a few large fleets.
How severe is this compared to similar codes
When we compare 391.45B to peer codes in the Driver Fitness category, the severity picture becomes clearer.
391.41APC—operating a property-carrying vehicle without a valid medical certificate in possession—has 49,539 citations and a 97.1% OOS rate. That code addresses the same medical fitness domain but focuses on the certificate not being physically available at the time of inspection. The extreme OOS rate reflects the immediate danger: a driver without proof of medical qualification cannot legally operate.
Contrast that with 391.45B's 15.9% OOS rate. Our data indicates that an expired certificate is treated as a correctable defect more often than a grounds for immediate removal. This likely reflects officer discretion: if you can demonstrate that you've scheduled a medical exam or that the certificate renewal is imminent, enforcement may proceed with a citation rather than out-of-service action.
391.41(a)—Physical qualification, general—shows 42,270 citations with a 16.2% OOS rate, nearly identical to 391.45B's rate. This suggests that violations in the physical qualification space that are technical or timing-related (rather than evidence of actual unfitness) are handled similarly across the category.
How to avoid it
Preventing a 391.45B citation begins with proactive medical certificate management:
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Know your certificate expiration date. Mark it in your phone, your logbook, and your fleet management system. Set a reminder 60 days before expiration so you have time to schedule and complete a new DOT medical exam without running out.
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Schedule your medical exam early. Don't wait until the last week. Approved medical examiners can have wait times, and if your current certificate expires while you're waiting for an appointment, you're in violation. Book at least 30 days ahead of expiration.
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Carry your original certificate or proof of filing. Our inspection data shows that 383.23A2 (operating a CMV without a CDL) commonly co-occurs with 391.45B in the same inspection—sometimes violations cluster because documentation is missing or disorganized. Keep your medical certificate in your cab or vehicle at all times, or ensure your state's licensing agency has it on file.
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Perform a pre-trip document check. Before every shift, verify that your medical certificate is still valid. It takes 10 seconds and prevents a roadside citation. Pair this with a general document review: your CDL, proof of periodic vehicle inspection, and current logbook.
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If you're driving a Freightliner, Kenworth, International, or Peterbilt, be extra cautious. Our data shows these makes account for 1,059 of the 1,782 391.45B citations. While this likely reflects their prevalence in the fleet, it underscores that drivers of high-volume commercial trucks face frequent roadside inspections. Compliance is higher stakes when you're inspected more often.
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Understand co-occurring violations. Our inspection records show that operating a CMV while ill or fatigued (code 392.2C) sometimes occurs with 391.45B. This suggests that some drivers with expired certificates may also be operating while fatigued or unfit. Your medical certificate is a gateway to confirming fitness; don't let it lapse and then compound the violation by driving tired.
The bottom line: 391.45B is preventable entirely through scheduling discipline. Unlike violations tied to equipment failure or driver decision-making in the moment, an expired medical certificate is a matter of calendar management. A single 15-minute phone call to book your DOT medical exam can eliminate this citation from your record.