The exam
Interstate CMV drivers must be medically examined and certified against the standards in 49 CFR §391.41 at least every 24 months (§391.45(b)). Drivers with insulin-treated diabetes certified under §391.46, and drivers who qualify under the alternative vision standard in §391.44, must be recertified at least every 12 months (§391.45(e) and (f)).
The exam must be administered by a medical examiner listed on the National Registry of Certified Medical Examiners (NRCME). The list is at nationalregistry.fmcsa.dot.gov.
Common disqualifying conditions
Common conditions that complicate CDL certification: insulin-treated diabetes (certified by the medical examiner after the treating clinician's ITDM assessment (Form MCSA-5870); no exemption needed (§391.46)), distant visual acuity worse than 20/40 in either eye even with corrective lenses, unless the driver meets the alternative vision standard in §391.44 (§391.41(b)(10)), failing the forced-whisper test at 5 feet, or an average hearing loss in the better ear over 40 dB at 500, 1,000 and 2,000 Hz, with hearing aid if used (§391.41(b)(11)), epilepsy without exemption, current alcoholism, and uncontrolled hypertension.
Many conditions allow continued certification with documentation, monitoring, and shorter recertification cycles. Drivers should not assume a condition disqualifies - consult the NRCME examiner.
How the certification flows
The medical examiner must electronically transmit the exam results (Form MCSA-5850) to FMCSA by midnight (local time) of the next calendar day after the exam (§391.43(g)(5)(i)(B)). Since June 23, 2025, the state receives an electronic copy of the medical certification from FMCSA for CDL and CLP holders and posts the medical status to the driver's CDLIS record (§383.71(h)).
Since June 23, 2025, the examiner issues a paper Medical Examiner's Certificate only to drivers who will not operate a CMV requiring a CDL or CLP (§391.43(g)(2)(ii)), and CDL and CLP holders no longer need to carry the certificate (§391.41(a)(2)(i)(B)). If the electronic information from FMCSA and a paper copy conflict, the electronic information controls (§391.41(a)(2)(iv)).