DOT physical: what the examiner checks, by the rule

The medical examination is defined by one section of the regulations, 49 CFR 391.41(b), which sets 13 standards a driver must meet. The numbers are precise — 20/40 vision in each eye, a 70-degree field, a forced whisper heard at 5 feet — and the certificate is good for 24 months unless a listed condition shortens it to 12.

A truck driver at the wheel of a cab on the highway — The medical certificate must be carried while driving a CMV in interstate commerce. Photo: Veronica538, CC BY-SA 3.0, via Wikimedia Commons (resized)

1Vision, each eye 20/40
2Whisper test 5 ft
3Certificate 24 months

Drawing with the page's key figures; the numbered callouts link to the calculators.

The 13 standards

Area	Standard (49 CFR 391.41(b))
Limbs	No loss of a foot, leg, hand or arm, or a Skill Performance Evaluation certificate under §391.49.
Limb impairment	No hand, finger, arm, foot or leg impairment that interferes with grasping or normal driving tasks, or an SPE certificate.
Insulin-treated diabetes	Permitted only under §391.46 (12-month certificate).
Cardiovascular	No current diagnosis of heart attack, angina, coronary insufficiency, thrombosis or other cardiovascular disease known to cause fainting, shortness of breath, collapse or congestive heart failure.
Respiratory	No established history or diagnosis of respiratory dysfunction likely to interfere with safe driving.
Blood pressure	No current diagnosis of high blood pressure likely to interfere with safe operation.
Musculoskeletal	No rheumatic, arthritic, orthopedic, muscular, neuromuscular or vascular disease interfering with safe control.
Epilepsy / loss of consciousness	No established history or diagnosis of epilepsy or any condition likely to cause loss of consciousness or control.
Mental or nervous	No mental, nervous, organic or functional disease or psychiatric disorder likely to interfere with safe driving.
Vision	20/40 or better in each eye and both eyes (corrected allowed); 70° horizontal field each eye; recognises red, green and amber.
Hearing	Forced whisper at 5 ft in the better ear, or average loss of 40 dB or less at 500, 1,000 and 2,000 Hz, hearing aid allowed.
Drugs	No use of Schedule I substances, amphetamines, narcotics or other habit-forming drugs; other scheduled drugs only when prescribed and the prescriber advises they will not affect safe driving.
Alcoholism	No current clinical diagnosis of alcoholism.

Vision, in detail

Distant visual acuity of at least 20/40 (Snellen) in each eye without corrective lenses, or corrected to 20/40 or better; at least 20/40 binocular; a horizontal field of at least 70 degrees in each eye; and the ability to recognise red, green, amber traffic signals. Glasses and contacts are fine and are noted on the certificate. A driver whose worse eye fails the corrected acuity or field standard can still qualify under the §391.44 alternative vision standard (12-month certificate).

Hearing, in detail

Either standard passes: perceive a forced whispered voice in the better ear at 5 feet, or, on an audiometer, an average hearing loss in the better ear of no more than 40 dB at 500, 1000, 2000 Hz. A hearing aid may be worn for either test, and the certificate then requires it while driving.

How often the medical certificate renews

Under 49 CFR 391.45 a driver must be examined and certified again if not certified in the preceding 24 months. Three groups are on a 12-month cycle: Insulin-treated diabetes (§391.46); Alternative vision standard (§391.44); Exempt intracity zone drivers (§391.62). And three situations require an examination regardless of the calendar: never been examined and certified; ability impaired by injury or disease; found not physically qualified under §391.43(g)(3) on or after 2025-06-23. Examiners may also certify for less than 24 months when a condition warrants monitoring.

What the rule does not say

Section 391.41 names conditions and sets numeric limits for vision and hearing only. It does not publish a blood-pressure cut-off or a blood-sugar figure in the regulation text itself; those thresholds live in FMCSA's medical examiner guidance, which this page does not reproduce. The regulation's words are what an examiner must apply, and they are what is quoted above.

CDL drivers: the medical certificate is tied to the licence through the state driver licensing agency. A lapsed certificate downgrades the CDL. Keep the renewal date with the Form 2290 and UCR dates on the same calendar.

Sources: 49 CFR 391.41(b) — Physical qualifications for drivers (eCFR); 49 CFR 391.45 — Persons who must be medically examined and certified (eCFR). Checked 2026-10-23.