DOT Physical Requirements: The 13 Standards of 391.41

Quick answer: Federal physical qualification for interstate commercial driving is defined by thirteen standards in 49 CFR 391.41(b) — covering limbs, diabetes, heart, lungs, blood pressure, musculoskeletal condition, seizures, mental health, vision, hearing, drug use, and alcoholism. Some standards are specific and measurable (vision's 20/40 and 70-degree field); many are written as "no clinical diagnosis likely to interfere with safe operation" — language a certified medical examiner applies to your case. Several have alternative qualification paths: 391.44 for vision, 391.46 for insulin-treated diabetes, the SPE certificate for limb impairments, and federal exemption programs. Not meeting a standard as written is the start of a process more often than the end of a career.

Medical-information disclaimer: Last reviewed July 19, 2026. This is general information, not medical advice, and it cannot tell you whether you qualify — only a certified medical examiner, applying these standards to your examination, makes that determination. Rules and guidance change; confirm current text with the eCFR and FMCSA. Not affiliated with FMCSA or any clinic.

How to read these standards

Three things to understand before the list. First, the regulation text is what binds; FMCSA's examiner guidance shapes how examiners apply it but is guidance, not law. Second, most standards hinge on the phrase likely to interfere with safe operation — which makes the examiner's judgment, informed by your history and records, the deciding instrument. Third, "the standard as written" is not always the last word: alternative paths exist for several conditions, which is exactly what the exemptions and variances guide maps.

The thirteen standards, in plain English

1. Loss of limb — 391.41(b)(1): loss of a hand, arm, foot, or leg. Not an automatic end: the SPE certificate path under 391.49 exists because skill can be demonstrated.

2. Limb impairment — (b)(2): an impairment that interferes with the ability to perform normal tasks of operating a CMV — same SPE path available.

3. Diabetes — (b)(3): the standard addresses diabetes requiring insulin; since 2018, 391.46 lets insulin-treated drivers qualify through their treating clinician plus the examiner. Full guide: Diabetes and the DOT Physical.

4. Cardiovascular — (b)(4): no current clinical diagnosis of heart conditions likely to cause sudden collapse — heart attack history, angina, and similar are evaluated with records, commonly with a cardiologist's input. Examiner judgment territory.

5. Respiratory — (b)(5): no respiratory dysfunction likely to interfere with safe operation. This is the standard under which examiners weigh conditions like untreated sleep apnea — there is no separate federal sleep-apnea rule, as the sleep-apnea guide explains.

6. High blood pressure — (b)(6): written qualitatively; the familiar numeric staging comes from FMCSA guidance, not the regulation. The distinction matters and gets its own page: Blood Pressure and the DOT Physical.

7. Musculoskeletal — (b)(7): no arthritic, orthopedic, muscular, or vascular condition likely to interfere — function is what the examiner is judging.

8. Epilepsy and seizures — (b)(8): no established medical history or clinical diagnosis of epilepsy or any condition likely to cause loss of consciousness or control. One of the stricter standards as written; a federal seizure exemption program exists for individually reviewed cases.

9. Mental and psychiatric — (b)(9): no mental, nervous, organic, or functional disease or psychiatric disorder likely to interfere. Treated, managed conditions are evaluated on evidence — this standard is about function, not a diagnosis label.

10. Vision — (b)(10): measurable — distant acuity of at least 20/40 in each eye and both together (corrective lenses allowed), at least a 70-degree horizontal field in each eye, and the ability to recognize standard traffic-signal colors. The alternative path when one eye cannot meet it is 391.44's individual assessment.

11. Hearing — (b)(11): measurable — perceive a forced whisper at 5 feet or meet the audiometric limit in the better ear, hearing aid permitted. An exemption program exists for drivers who cannot meet it.

12. Drugs — (b)(12): does not use certain controlled substances, with a narrow exception for a non-Schedule-I substance prescribed by a practitioner familiar with the driver's history and duties. The full mechanics: Medications and the DOT Physical.

13. Alcoholism — (b)(13): no current clinical diagnosis of alcoholism — "current" being the operative, clinically determined word.

Where the deciding actually happens

The exam that applies all thirteen is the DOT physical itself — one appointment, one examiner, working through Form MCSA-5875 with your history in front of them. For most drivers most standards are a non-event; where one is in play, the examiner can certify, certify for a shorter monitoring period, ask for records, or decline — and disagreements between medical opinions have their own federal resolution process under 391.47.

A worked illustration (not medical advice)

A driver with well-controlled type 2 diabetes (no insulin) and mild, treated high blood pressure reads the list above and worries about standards (b)(3) and (b)(6). At the exam, the diabetes is evaluated as an ordinary managed condition; the blood pressure earns a one-year certificate under the examiner's guidance-informed judgment rather than a two-year card. Neither standard "failed" the driver — both routed through the examiner's evaluation, which is how the system is built to work. (Illustration of how the standards are applied, not medical advice; outcomes depend on your examination.)

Common mistakes

• Reading the list as pass/fail switches. Most standards route through examiner judgment and several have alternative paths — the list is a map, not a verdict.
• Assuming a diagnosis equals disqualification. The standards mostly target conditions likely to interfere with safe operation — managed and documented is a different conversation than untreated and undisclosed.
• Not knowing the alternative paths exist. 391.44, 391.46, the SPE certificate, and the exemption programs exist precisely for drivers who miss a standard as written.
• Treating internet charts as regulation. Numeric thresholds you see online for blood pressure are guidance — the regulation's own words are broader.
• Skipping the records. Standards that hinge on judgment are decided on evidence; arriving without it invites a delay.

Your standards checklist

• The thirteen categories skimmed against your own history — before the appointment
• Records gathered for any condition an examiner will want evidence on
• Alternative paths understood if one applies (391.44 / 391.46 / SPE / exemption programs)
• Medications listed with prescribers — how they are evaluated
• The exam itself previewed, start to finish

Keep learning

• The exam walkthrough: The DOT Physical: What to Expect · the credential: The DOT Medical Card
• Deep dives: Vision and Hearing · Blood Pressure · Exemptions and the SPE
• Start your CDL journey right: TLWS Academy · free CDL Pre-School · join the email list.