Drivers who must meet the federal physical-qualification rules need a medical examination and certification. Here is what 49 CFR 391.45 says about who, and how often.
The short answer
At least every 24 months. A driver who has not been medically examined and certified in the preceding 24 months must be examined again. Some drivers need it more often: every 12 months.
Who must be examined and certified (49 CFR 391.45)
- Any person who has never been medically examined and certified as physically qualified to drive a commercial motor vehicle.
- Any driver who has not been examined and certified during the preceding 24 months.
- Any driver whose ability to perform normal duties has been impaired by a physical or mental injury or disease.
The examination is done under 49 CFR 391.43 by a medical examiner.
When 12 months applies
The rule sets a shorter period for these cases:
- A driver with insulin-treated diabetes who holds a medical examiner’s certificate under § 391.46, if the last examination was not within the preceding 12 months.
- A driver who does not meet the distant visual acuity or field-of-vision standard with the worse eye and holds a certificate under § 391.44, if the last examination was not within the preceding 12 months.
- A driver limited to an exempt intracity zone (§ 391.62), if the last examination was not within the preceding 12 months.
Practical tips
- Put the renewal date in your phone as soon as you get your certificate.
- Ask your state licensing agency how it wants you to submit the certificate. State procedures differ.
- Intrastate and exempt drivers can have different rules; confirm with your state.
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Official sources
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Facts checked against the official text of 49 CFR (eCFR) as current on October 15, 2026. Rules change and each state adds its own: confirm with your DMV and the FMCSA. PassYourCDL is an independent study site, not affiliated with the FMCSA, the DOT or any DMV, and this is not legal advice.