§391.45 lists the situations in which a driver must be medically examined: before driving a CMV unless examined and certified during the preceding 24 months; after the medical-certificate expiration; after any injury or illness that impairs ability to perform driving duties (§391.41(b) standards); and after a change in condition that affects qualification under §391.41. The 24-month interval is the outer limit, not the only trigger — the post-condition re-exam requirement is routinely under-enforced.
Severity weight
Severity weight 3 in the Driver Fitness BASIC. A pattern of expired or missing medical certificates is one of the most common new-entrant audit findings under §385.321(b)(1).
What triggers a new exam
- 24-month re-exam under §391.45(b)(1).
- Post-injury or post-illness re-exam under §391.41(b) when the condition affects driving ability.
- Certificate issued for less than 24 months — the shorter interval governs (a 1-year certificate due to controlled hypertension, for example).
- After a Skill Performance Evaluation (SPE) certificate change.
How to prevent it
- Track the medical-certificate expiration as a discrete date, not a generic file-review date.
- Add a §391.45(b)(2) check to the post-incident workflow — any qualifying injury triggers a re-exam.
- For CDL drivers, the §391.51(b)(6)(ii) CDLIS MVR med-cert status replaces the carrier-filed certificate but does not replace the §391.45 examination requirement itself.
How Roadworthy HQ helps
Roadworthy HQ tracks the §391.45 next-exam date as a separate field, fires 60- and 30-day reminders before expiration, and surfaces post-incident triggers from the driver record to the §391.45(b)(2) re-exam workflow.