FMCSR 391.45F: Operating While Medically Impaired

391.45F citation for operating a CMV while impaired by physical or mental condition discovered after medical certification. Enforcement data, consequences, and prevention steps.

Severity Weight
N/A
OOS Eligible
No
BASIC Category
Driver Fitness
Code System
FMCSR
Code:
391.45F
Code System:
FMCSR
BASIC Category:
Driver Fitness
OOS Eligible:
No
Severity Weight:
N/A

Ranks #2,664 of 3,146 FMCSR codes by citation frequency • OOS rate of 0.0% is below the FMCSR-wide average of 33.3%.

Violation Description

Medical (Certificate) - Operating a commercial motor vehicle when impaired by a physical or mental injury or disease discovered after current medical certificatio

In-Depth Explainer

Grounded in TruckCodex roadside-inspection data

What 391.45F means in plain language

FMCSR 391.45F addresses a specific medical fitness scenario: you are operating a commercial motor vehicle while experiencing a physical or mental injury, illness, or condition that was discovered after you obtained your current medical certificate. This is distinct from lying on your medical exam or failing to disclose a pre-existing condition at the time of certification.

In practical terms, this violation applies when something happens to you—an injury you sustain, an illness you develop, or a medical condition that emerges—between your medical certification and the moment a roadside inspector determines you are impaired by that condition and unfit to drive safely. The inspector's job is to identify whether your current medical certificate remains valid given your actual physical or mental state at that moment.

This is not about expired certifications or missing documents. It is about your fitness to operate a CMV on the day you are inspected, based on conditions that arose after your last successful medical clearance.

What our enforcement data actually shows

Across our 13 million+ inspection records, 391.45F is one of the rarest citations issued. Our database shows only 2 all-time citations for this violation, with zero citations in the last 12 months and zero in the last 90 days. This code ranks #2,651 of 3,036 FMCSR codes by citation volume.

Of those 2 all-time citations, neither resulted in an out-of-service order. The OOS rate for 391.45F is 0.0%, which is substantially lower than the all-FMCSR average OOS rate of 31.4%. In practical terms, roadside enforcement of 391.45F is extremely uncommon, and when it does occur, drivers are typically not placed out of service immediately.

The rarity of this citation does not diminish its regulatory importance, but it does signal that most drivers either maintain their medical fitness throughout their certification period, or inspectors do not frequently detect and cite post-certification medical impairment in the roadside environment.

Who gets cited most

Our enforcement records do not provide sufficient state-level citation distribution for 391.45F to identify clear geographic patterns. However, we can note that the 2 all-time citations in our database were issued to carriers including Gray Fleet Corp (USDOT 2538564) and Rocket City Movers of Huntsville Inc (USDOT 3506310), each with one citation. This extremely limited sample size means state and carrier risk profiles are not statistically meaningful for this violation.

How severe is this compared to similar codes

391.45F sits within the Driver Fitness category alongside several other medical certificate and physical qualification codes. For context:

391.41APC (Operating without a valid medical certificate in possession or on file) shows 49,539 citations with a 97.1% OOS rate—vastly more frequent and punitive than 391.45F.

391.41(a) (Physical qualification general) has 42,270 citations with a 16.2% OOS rate, indicating that general fitness violations are cited far more often but with lower OOS severity.

383.23(a)(2) (CDL wrong class) leads the category with 50,385 citations and a 98.4% OOS rate, reflecting the FMCSA's focus on licensing compliance over post-certification medical discovery.

The comparison underscores that 391.45F is a narrowly-scoped violation—it applies only to conditions discovered after certification—whereas related codes address certification gaps, missing documents, or general unfitness that inspectors can verify more readily during routine inspections.

How to avoid it

Preventing a 391.45F citation requires honest self-assessment and medical awareness between your certification renewals:

  • Report new injuries or illnesses to your carrier and medical provider immediately. If you suffer an injury while on duty or develop symptoms of a medical condition (severe headaches, vision changes, chest pain, mental health concerns), notify your fleet safety team and seek medical evaluation before continuing to operate. Do not wait until roadside inspection.

  • Know the medical standards your certificate was issued under. Your medical examiner certified you against specific FMCSA criteria (vision, hearing, blood pressure, diabetes control, cardiovascular fitness, etc.). If you experience changes in any of these areas—blurred vision, hearing loss, uncontrolled hypertension, or fainting episodes—consult your examiner or physician.

  • Do not assume your certificate covers new conditions. Your medical certificate is valid only for the conditions you disclosed and the health status you had at the time of exam. New diagnoses are not automatically covered. Proactively obtain medical clearance before returning to duty if anything material changes.

  • Maintain a pre-trip fitness check. Before each shift, conduct a basic self-assessment: Am I rested? Am I experiencing pain, dizziness, or vision problems? Am I mentally alert? This informal check can catch deterioration early and prompt medical follow-up before an inspector does.

  • Keep your certification documentation current and accessible. Carry proof of your valid medical certificate and any supporting medical records. If questioned at roadside, transparent communication with the inspector and willingness to undergo medical re-evaluation can limit citation severity.

Last updated: 2026-04-20T17:43:23.380Z Based on TruckCodex inspection data See 391.45F Q&A → Fleet FAQ →

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