Federal rules say a commercial truck driver may not drive unless medically certified as physically qualified, and a driver not examined and certified in the preceding 24 months must be examined again. When a crash follows a blackout, a seizure, a heart event or a driver who fell asleep, an injury claim asks whether the driver should have been behind the wheel and what the carrier knew.
The short version
- A driver must be medically certified. Under 49 CFR § 391.41(a)(1)(i), a person “must not operate a commercial motor vehicle unless he or she is medically certified as physically qualified to do so.”
- The standards are specific. Section 391.41(b) lists 13 conditions or limits, among them epilepsy “or any other condition which is likely to cause loss of consciousness,” heart disease, respiratory dysfunction, vision, hearing and drug use.
- The exam repeats. A driver not certified during the preceding 24 months must be examined again (§ 391.45(b)); some conditions require it every 12 months.
- The carrier has its own duty. It may not “require or permit” a driver to drive while illness or fatigue makes it unsafe (§ 392.3), and § 391.51 requires its driver qualification file to hold proof of medical certification.
- Health risks are measurable. In a CDC-archived 2010 survey of 1,670 long-haul drivers, 69 percent were obese against 31 percent of working U.S. adults.
What medical standards must a truck driver meet?
Thirteen physical qualification standards in 49 CFR § 391.41(b). They cover limbs, insulin-treated diabetes, heart disease, respiratory dysfunction, high blood pressure, epilepsy and conditions that cause loss of consciousness, mental disorders, vision, hearing, drug use and alcoholism.
Paragraph (a)(1)(i) of the rule says a person subject to the part “must not operate a commercial motor vehicle unless he or she is medically certified as physically qualified to do so.” The carrying requirement changed in 2025: paragraph (a)(2)(i)(B) says that on or after June 23, 2025 a driver who holds a commercial driver’s license or learner’s permit “no longer needs to carry on his or her person” the medical examiner’s certificate. These standards sit beside the other explanations in the common causes of Houston truck crashes.
| Paragraph | What the regulation says | A related rule or record |
|---|---|---|
| (b)(3) | No established history or diagnosis of diabetes mellitus “currently treated with insulin for control,” unless the person meets § 391.46. | Section 391.46 requires a treating-clinician evaluation and an exam at least annually. |
| (b)(4) | No current clinical diagnosis of myocardial infarction, angina pectoris, coronary insufficiency, thrombosis or other cardiovascular disease “of a variety known to be accompanied by syncope, dyspnea, collapse, or congestive cardiac failure.” | The examiner records findings on the Medical Examination Report (§ 391.43(f)). |
| (b)(5) | No history or diagnosis of “a respiratory dysfunction likely to interfere with his/her ability to control and drive a commercial motor vehicle safely.” | Sleep apnea is analyzed under this paragraph (see below). |
| (b)(8) | No history or diagnosis of epilepsy “or any other condition which is likely to cause loss of consciousness or any loss of ability to control a commercial motor vehicle.” | Any FMCSA medical variance relied on must be kept in the driver qualification file (§ 391.51(b)(6)(iii)). |
| (b)(12) | No use of a Schedule I drug, an amphetamine, a narcotic or other habit-forming drug; other controlled substances only if prescribed by a practitioner who has advised the driver they will not affect safe driving. | Post-crash testing is a separate rule; see proving drug use by truck drivers. |
Source: 49 CFR § 391.41 and § 391.43, read on the eCFR on 16 October 2026. The table quotes selected paragraphs; the regulation has the full list.
How often must a commercial driver be medically examined?
At least every 24 months for most drivers. Section 391.45(b) requires an exam for any driver not certified during the preceding 24 months, and the rule also reaches a driver whose ability to work has been impaired by a physical or mental injury or disease.
The exam rule is § 391.45. Paragraph (a) covers anyone never examined and certified, and paragraph (e) applies a 12-month look-back to a driver with insulin-treated diabetes. Paragraph (g) is the one that matters most after an illness: a driver “whose ability to perform his or her normal duties has been impaired by a physical or mental injury or disease” must be examined and certified.
That rule puts a duty on the calendar between routine exams. If an illness or injury has impaired a driver’s ability to perform normal duties, a certificate issued a year earlier does not by itself settle the question. In a crash investigation the dates come first: the last certificate, any illness or leave, and the day the driver was dispatched again. Preserving the records that show them is the subject of the evidence article on 18-wheeler claims.
Who is allowed to perform a DOT physical?
A medical examiner listed on the National Registry of Certified Medical Examiners. Section 391.43(a) says the exam “must be performed by a medical examiner listed” on the Registry, with narrow exceptions for the vision part (eye doctors) and for veterans (certified VA examiners).
FMCSA’s National Registry page explains the system. An examiner must be licensed, certified or registered under state law, register with the Registry, complete training based on the federal rules and pass a certification test. Once certified, the examiner must upload results for every exam “by midnight (local time) of the next calendar day following the examination.” Drivers can search by city and state or zip code, and advanced search accepts a name or National Registry number.
So a driver’s certificate can be traced to a named examiner. The examiner must keep the report and a copy of the certificate “for at least 3 years from the date of examination” (§ 391.43(i)). On or after June 23, 2025, an examiner who finds a driver not physically qualified must tell the driver the finding will be reported to FMCSA, and earlier certificates stop satisfying § 391.41(a) (§ 391.43(g)(3)).
Can a driver with sleep apnea or diabetes still drive a truck?
Sometimes, yes. The regulation does not name sleep apnea; it bars a respiratory dysfunction “likely to interfere” with safe driving, and it allows insulin-treated diabetes only if the driver meets the evaluation and annual-exam rules in § 391.46. Control of the condition matters, not the diagnosis alone.
On sleep apnea, FMCSA’s page titled “Where can I find the 2015 OSA Bulletin?” carries a caution: “This guidance was rescinded on January 22, 2024, and is no longer in effect,” citing 89 FR 3892. The preserved bulletin says sleep apnea “is considered a respiratory dysfunction when there is a determination that it is likely to interfere with the driver’s ability to operate safely because of the severity of the case,” and that FMCSA’s standards “do not provide OSA screening, diagnosis or treatment guidelines.” Those statements describe the 2015 view, so they are best read as history, and the regulation itself, § 391.41(b)(5), controls.
Insulin-treated diabetes has an explicit pathway: a driver is qualified if he or she otherwise meets § 391.41, has the treating-clinician evaluation on Form MCSA-5870, and is examined at least annually. Heart disease and epilepsy have their own paragraphs, as the table shows. Whether a driver met a standard turns on records, and an attorney should review it rather than assume it.
What does a trucking company have to do when a driver is sick or exhausted?
It may not require or permit the driver to drive. Under § 392.3, no driver may operate, and the carrier may not require or permit operation, while ability or alertness is so impaired, or so likely to become impaired, through fatigue, illness or any other cause as to make it unsafe.
This rule reaches past the exam. A valid certificate says a driver met the standards on the day of the exam; the duty to stay off the road when unsafe applies every day. Dispatch practices, delivery deadlines and what a dispatcher knew about a driver’s condition become relevant here, as does the schedule analysis in the hours-of-service explainer.
Whether a carrier knew of a condition can change the claims against it; the Texas standard for exemplary damages is covered in the piece on proving gross negligence against a carrier, and it is a question of proof; fault the other way is covered in comparative negligence in Texas. Which companies can be named is in the truck liability article, and a carrier based outside Texas raises the questions in choosing a lawyer for an interstate truck crash.
How common are health risks among long-haul truck drivers?
More common than in the working population, according to a 2010 survey archived by the CDC: 69 percent of 1,670 long-haul drivers were obese against 31 percent of working U.S. adults, 51 percent were current smokers against 19 percent, and 61 percent reported two or more risk factors.
The survey, “Obesity and Other Risk Factors: The National Survey of U.S. Long-Haul Truck Driver Health and Injury,” collected data in 2010 at 32 truck stops across the 48 contiguous states, and the results are self-reported. It is more than a decade old and describes a group, not any one driver.
The numbers do not show that a driver with a risk factor caused a crash; a driver with a risk factor is not automatically disqualified, and § 391.41(b)(6) bars high blood pressure “likely to interfere” with safe operation, not every diagnosis. They show why an investigation asks what was diagnosed, what was treated and what the carrier was told, a review done by the specialists in expert witnesses in truck cases.
Where is a driver’s medical certificate kept?
In the driver qualification file the carrier must keep for each driver it employs. Section 391.51(b)(6) requires the medical examiner’s certificate or a legible copy there or, for commercial license holders, the state driver record showing medical certification status. How long the file must be kept is covered in the evidence post.
Under § 391.51, the file holds more than the certificate. It includes the application, motor vehicle records, any FMCSA variance paperwork and a note confirming that the examiner was listed on the National Registry in the cases the regulation describes. The carrier controls the file; how to ask it to preserve records is in the evidence article.
The state side is on the Texas Department of Public Safety’s commercial driver license medical certification page. It says a current medical examiner’s certificate may have to be on file with DPS, depending on the type of driving the holder self-certifies, that it must stay valid to avoid a downgrade of the license, and that since June 23, 2025 certified medical examiners must send exam results to DPS electronically through the National Registry.
A medical certificate can also be checked at the roadside. The Houston Police Department’s Truck Enforcement Unit says a Level I North American Standard Inspection includes examination of the driver’s license, the medical examiner’s certificate and Skill Performance Evaluation certificate if applicable, alcohol and drugs, and the driver’s record of duty status and hours of service (Houston Police Department, Truck Enforcement Unit, Safety Inspections). Our pages on Baytown and Galveston truck crashes cover claims on the roads east of the city.
A driver’s medical history is private, and records generally come through the legal process, not a phone call to the carrier. That is why the first steps in what to do after a truck accident include noting the USDOT number and company name at the scene, and why the list of mistakes to avoid after a truck crash warns against casual statements to the carrier.
Has a driver’s medical emergency caused a Houston truck crash before?
Yes. The Houston Chronicle reported on April 5, 2012 that an 18-wheeler driver died after a heart attack caused him to leave the westbound I-610 service road near Lavender and drive into a front yard, stopping short of a house. No one else was hurt.
According to the Chronicle’s report, investigators said the driver, traveling from Arkansas through Texas, suffered a heart attack on the I-610 service road, veered off, and was found dead in the cab about 5 a.m.; the truck stopped in the front yard of a home in the 5500 block of Lavender. The article says nothing about the driver’s medical certificate or the carrier.
A more recent Houston story involves a disputed medical event. ABC13 reported on September 11, 2025 that a Louisiana trucker who led Harris County deputies on an almost hour-long pursuit along the East Freeway in December 2023, at speeds of no more than five miles per hour, is suing the deputies. His attorney says sepsis made him black out; the county’s court filing says he “did not appear to be suffering from a medical emergency.” The story concerns the deputies’ response and says nothing about the driver’s medical certificate; whether anyone else was hurt is a separate question for a Houston personal injury attorney.
When people in other vehicles are hurt, the claim runs through the carrier’s coverage, described in how a carrier’s insurance responds, and the contrast with car claims is in the 18-wheeler overview. Families who have lost someone can read the wrongful death page.
What can an injured person ask about a driver’s medical fitness?
Five things: whether the driver held a valid medical examiner’s certificate on the crash date, who the examiner was, whether any variance applied, whether the driver was ill or off duty before the crash, and what the carrier knew. Each question points to a specific record.
The certificate and variance are in the driver qualification file, and the examiner can be looked up on the National Registry. Illness, leave and dispatch records come from the carrier and the driver. Medical incapacity is one hypothesis among several, and the pieces on distracted truck drivers and trucks that fail to stop cover the others that must be ruled in or out. Your own treatment records matter too: see sharing medical records with an adjuster, and how long a Texas injury case takes.
The 18-wheeler accident page describes the firm’s truck practice, the settlement page covers what compensation can include, and the same crash on a road near Sugar Land, Katy or Pasadena has its own page. For the work a lawyer does on such a claim, see how a truck accident lawyer builds the case. Fee terms are covered in what a Houston accident lawyer charges; the crash date, the carrier’s name and any medical event the driver reported can go to a lawyer through the contact form.
Frequently asked questions
What is a DOT physical?
It is the medical examination federal rules require before a person can drive a commercial motor vehicle. Under 49 CFR § 391.41(a), the driver must be medically certified as physically qualified, and under § 391.43(a) the exam must be done by a medical examiner listed on the National Registry of Certified Medical Examiners.
What does a DOT physical consist of?
The examiner performs the exam and records the results on the Medical Examination Report form, MCSA-5875 (§ 391.43(f)). The exam tests against the standards in § 391.41(b), which include vision of at least 20/40 in each eye, a 70-degree field of vision in each eye, hearing, heart, blood pressure, epilepsy and drug-use standards.
What are the new DOT physical requirements?
The eCFR text shows changes on or after June 23, 2025: a driver with a commercial license or learner’s permit no longer has to carry the medical examiner’s certificate (§ 391.41(a)(2)(i)(B)), and an examiner who finds a driver not physically qualified must tell the driver the finding will be reported to FMCSA (§ 391.43(g)(3)).
Where can I get a DOT physical?
From a certified medical examiner listed on FMCSA’s National Registry. FMCSA says drivers can search the Registry by city and state or by zip code, and use advanced search to look up an examiner by name, business name or National Registry number.
How long is a trucker’s medical certificate good for?
Section 391.45(b) requires an exam for a driver who has not been certified during the preceding 24 months, so 24 months is the general outer limit. Insulin-treated diabetes requires another exam if the most recent one was not within the preceding 12 months.
Can a trucking company let a driver with a health problem keep driving?
No, not when the condition makes driving unsafe. Section 392.3 puts that duty on the carrier as well as the driver. Its only exception lets a driver continue to the nearest place where the hazard is removed in a grave emergency where compliance would increase the hazard.
About the authors
Sam A. Maida, Jr.
Owner and Managing Attorney
Sam A. Maida, Jr. has represented injured Texans in the greater Houston area since the firm opened in 1993.
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Bernard G. Johnson III
Litigation Managing Attorney
Bernard G. Johnson III is a board certified trial lawyer licensed in Texas since 1996 and a graduate of South Texas College of Law.