DOT Physical Diabetes Requirements: A1C, Insulin & FMCSA Rules
This article is for general information only and is not medical advice. If you have been diagnosed with diabetes, talk to your treating doctor before your DOT physical — especially if you use insulin.
Does Diabetes Disqualify You From a DOT Physical?
The Short Answer
Diabetes does not automatically disqualify you from passing a DOT physical. Drivers who don't use insulin have no diabetes-specific federal standard and can be certified for up to the normal 2-year maximum. Drivers who use insulin can qualify under 49 CFR 391.46, but need Form MCSA-5870 from their treating clinician, a stable insulin regimen, properly controlled diabetes, and electronic glucose records — and their certificate lasts no more than 12 months.
- Diabetes controlled with diet, exercise, or oral medication (no insulin): There is no diabetes-specific federal standard. You can be certified for up to the normal 2-year maximum, though the examiner may choose a shorter period to monitor you.
- Insulin-treated diabetes: You can drive a truck. You need a completed Insulin-Treated Diabetes Mellitus Assessment Form (MCSA-5870) from the clinician who prescribes your insulin, and your certificate is limited to a maximum of 12 months.
- Insulin users without 3 months of electronic glucose records: At the medical examiner's discretion, you may qualify for a certificate of up to 3 months while you build the required record history.
- Not disqualifying on their own: Having diabetes, taking insulin, or your A1C number. What matters is a stable insulin regimen, proper control, and no serious complications.
- Disqualifying for insulin-treated drivers: Not maintaining a stable insulin regimen or properly controlling diabetes; severe non-proliferative or proliferative diabetic retinopathy (permanent); or a severe hypoglycemic episode, which prevents CMV operation until a treating clinician clears you. Non-insulin-treated diabetes has no specific disqualification list — the examiner evaluates it case by case.
What's In This Guide
DOT Diabetes Chart
| Your Situation | What's Required | Maximum Certification |
|---|---|---|
| Diabetes managed with diet, exercise, or oral medication | Standard DOT exam; examiner evaluates control and complications | Up to 2 years (examiner may certify for less) |
| Insulin-treated, stable regimen, 3+ months of electronic glucose records | MCSA-5870 from your treating clinician; exam within 45 days of the form being signed | Up to 12 months |
| Insulin-treated, but less than 3 months of electronic glucose records (for example, recently started insulin) | MCSA-5870 from your treating clinician | Up to 3 months, if the examiner qualifies you |
| Insulin-treated, regimen not stable or diabetes not properly controlled | — | Not qualified until stable and controlled |
| Insulin-treated with severe non-proliferative or proliferative diabetic retinopathy | — | Not qualified on a permanent basis |
| Insulin-treated, severe hypoglycemic episode after being certified | Stop driving; report to and be evaluated by a treating clinician; new MCSA-5870 | Prohibited from driving until cleared |
Source: 49 CFR 391.41(b)(3); 49 CFR 391.46; 49 CFR 391.45; FMCSA Medical Examiner's Handbook, 2024 Edition
Important: These are maximums. A medical examiner can always certify you for a shorter period if they want to monitor you more closely, and your overall certification also depends on every other DOT standard — blood pressure, vision, heart health, and so on.
Can You Pass a DOT Physical With Diabetes?
Yes. Diabetes by itself does not disqualify you from driving a commercial motor vehicle, and neither does insulin.
The federal physical qualification standard, 49 CFR 391.41(b)(3), says a driver must have no established medical history or clinical diagnosis of diabetes mellitus currently treated with insulin for control — unless the driver meets the requirements in 49 CFR 391.46. Section 391.46 is the insulin rule, and it spells out exactly how an insulin-treated driver qualifies.
If you don't use insulin, that standard doesn't apply to you at all. FMCSA has no diabetes-specific standard for drivers who manage their diabetes with diet, exercise, or oral medication. The examiner still looks at how well your diabetes is controlled and whether it has caused complications, and evaluates those under the other DOT standards.
Is There an A1C Cutoff for a DOT Physical?
The A1C Myth
Not in the federal rules. Neither 49 CFR 391.41 nor 391.46 sets a specific A1C number you must be under. You may see "A1C under 10%" or similar figures online — some examiners use a number like that as a personal rule of thumb, but it is not a federal requirement.
That doesn't mean your A1C is irrelevant. FMCSA's optional Non-Insulin-Treated Diabetes Mellitus Assessment Form (MCSA-5872), which an examiner may send to your doctor with your consent, asks whether your A1C has been measured over the past 12 months and requests the most recent result. It also asks about your diabetes medications, severe low-blood-sugar episodes, and complications such as kidney disease, heart disease, neuropathy, and retinopathy. Expect the examiner to look at the whole picture, not one lab value.
Insulin-Treated Diabetes: How the DOT Rule Works
Before 2018, drivers who used insulin generally needed a federal exemption to drive interstate. A 2018 FMCSA rule replaced that system with the 391.46 standard, and the Federal Diabetes Exemption Program has since ended. Today, a certified medical examiner can qualify an insulin-treated driver directly if the following steps are met.
Get evaluated by your treating clinician
Before each DOT exam, you must be evaluated by your "treating clinician" — defined in the rule as the healthcare professional who manages your diabetes and prescribes your insulin. During that visit, they complete the Insulin-Treated Diabetes Mellitus Assessment Form, MCSA-5870, then sign and date it with their full name, office address, and phone number.
Bring your glucose records to that visit
You must self-monitor your blood sugar as your treating clinician directs, using an electronic glucometer that stores every reading, records the date and time, and allows the data to be downloaded electronically. At the evaluation, you provide your clinician with a printout of those records or the glucometer itself. To qualify for a full certificate of up to 12 months, you need at least the preceding 3 months of these records while on insulin.
See the DOT examiner within 45 days
Your DOT exam must happen no later than 45 days after your treating clinician signs and dates the MCSA-5870. The examiner must receive the completed form, and it becomes part of your exam record. If the form is older than 45 days, plan on getting a new one.
The examiner makes the call
The medical examiner considers the MCSA-5870 but uses independent medical judgment. Under the rule, the examiner must find you are not qualified if you are not maintaining a stable insulin regimen and not properly controlling your diabetes. The examiner also checks that you are free of diabetes complications that could impair safe driving.
Repeat at least every year
Insulin-treated drivers must be examined and recertified at least annually. The maximum certificate length is 12 months — it can be shorter, but never longer.
What Will Disqualify a Driver With Diabetes?
For insulin-treated drivers, 49 CFR 391.46 lists specific situations in which a driver is not physically qualified:
The driver is not qualified if they are not maintaining a stable insulin regimen and not properly controlling their diabetes.
A driver with severe non-proliferative diabetic retinopathy or proliferative diabetic retinopathy is not qualified on a permanent basis. FMCSA's handbook notes this retinopathy rule applies to insulin-treated drivers — not to non-insulin-treated diabetes or retinopathy generally.
Without at least 3 months of compliant electronic glucose records, the driver cannot be certified for more than 3 months — and may qualify for up to 3 months only if the examiner finds them otherwise qualified.
A severe low-blood-sugar episode after certification bars the driver from operating a CMV until cleared (see below).
For drivers who don't use insulin, there is no list like this. Instead, the examiner weighs whether your diabetes or its complications fall under another standard — for example, FMCSA's handbook says non-insulin-treated diabetes could be considered under the standard for conditions likely to cause loss of consciousness (49 CFR 391.41(b)(8)).
DOT Diabetes Examples: Will You Pass?
| Driver Situation | Likely DOT Outcome |
|---|---|
| Type 2, diet and exercise only, no complications | No diabetes-specific rule; potentially up to a 2-year certificate |
| Type 2 on metformin, well controlled | No diabetes-specific rule; examiner evaluates control and complications; potentially up to 2 years |
| On insulin for a year, stable, brings MCSA-5870 and glucometer data | Up to a 12-month certificate |
| Started insulin 5 weeks ago, has MCSA-5870 | May qualify for a certificate of up to 3 months; up to 12 months once 3 months of records and a new MCSA-5870 are provided |
| On insulin, shows up without an MCSA-5870 | Cannot be certified under the insulin standard at that visit |
| On insulin, MCSA-5870 signed 60 days ago | Form is outside the 45-day window; a new one is needed |
| On insulin, frequent dose changes and erratic readings | Not qualified until the regimen is stable and diabetes is controlled |
| On insulin, diagnosed with proliferative diabetic retinopathy | Not qualified on a permanent basis |
Why DOT Diabetes Rules Are Different From Your Doctor's Goals
Your doctor manages your diabetes to protect your long-term health, and may set tight blood sugar and A1C targets. The DOT exam asks a narrower question: is your condition likely to interfere with safely operating a commercial motor vehicle right now?
That's why a driver whose doctor wants better numbers can still pass, and why a driver with "good" numbers can still have trouble if they've had a severe low or have developed serious eye disease. For insulin users in particular, the DOT focuses on a stable regimen, documented control, and the absence of severe hypoglycemia and serious complications.
Severe Hypoglycemia: What Happens If Your Blood Sugar Crashes
Under 49 CFR 391.46(e), a severe hypoglycemic episode is one that requires the assistance of others, or results in loss of consciousness, seizure, or coma.
If You Have a Severe Low After Being Certified
If an insulin-treated driver has a severe episode after being certified, they are prohibited from operating a CMV and must report it to, and be evaluated by, a treating clinician as soon as reasonably practicable. The prohibition continues until a treating clinician:
- Determines the cause of the episode has been addressed;
- Determines the driver is maintaining a stable insulin regimen and proper control; and
- Completes a new MCSA-5870.
The driver keeps that new form and brings it to their next DOT exam. The medical certificate doesn't automatically disappear, but the driver may not drive a CMV until those three conditions are met.
Oral Medications, GLP-1s, and Other Non-Insulin Treatment
The 391.46 standard is written specifically for diabetes "treated with insulin for control." If your treatment plan doesn't include insulin, the insulin requirements — the MCSA-5870, the electronic glucose records, and the 12-month cap — don't apply to you under that rule.
The examiner will still ask about your medications. Some diabetes drugs can cause low blood sugar, and the examiner is expected to consider medication side effects and your risk of losing consciousness. If you take a non-insulin injectable, tell the examiner exactly what it is so there's no confusion about which rules apply.
First DOT Physical vs. Recertification With Diabetes
What happens at your exam can depend on more than whether you have diabetes, including:
- Whether you use insulin, and for how long
- Whether you have at least 3 months of electronic glucose records
- How recently your treating clinician signed your MCSA-5870
- Any severe low-blood-sugar episodes in your history
- Eye exam findings, especially diabetic retinopathy
- Complications such as neuropathy, kidney disease, or heart disease
- Your blood pressure — diabetes and hypertension frequently occur together (see our DOT physical blood pressure guide)
What to Bring to Your DOT Physical If You Have Diabetes
If you use insulin (required items first):
- Your completed, signed MCSA-5870, dated within the last 45 days
- Your glucose records or glucometer, if the examiner asks for them
- A current medication list, including insulin type and dosing
- Your treating clinician's contact information
- Recent eye exam results, if you have them
If you don't use insulin:
- A current medication list
- Your doctor's contact information
- Recent lab results such as your A1C, if available
- Any records the examiner has specifically requested, such as an MCSA-5872
Beyond the MCSA-5870 for insulin users, this isn't a federally required checklist — but having the information on hand can help the examiner and may avoid delays.
How to Prepare for Your DOT Physical With Diabetes
The goal is an honest, well-documented picture of your health — not a one-day number. A lower reading on exam day doesn't change your actual risk on the road.
- Take your medications and insulin exactly as prescribed — don't skip doses or add extra to change your numbers
- Schedule your treating clinician visit so your DOT exam falls within 45 days of the MCSA-5870 being signed
- If you're starting insulin, begin keeping electronic glucometer records right away — you'll need 3 months for a full-length certificate
- Stay current on eye exams, since serious retinopathy affects insulin-treated drivers' qualification
- Be honest about any severe low-blood-sugar episodes — the rules around them exist to keep you and others safe
- Talk to your doctor well before your exam, not the morning of
Example: Driver Recently Started on Insulin
Real-World Example
A CDL driver with Type 2 diabetes is moved from oral medication to insulin in March. His medical certificate expires in May. He sees his treating clinician in late April, brings his glucometer, and gets a signed MCSA-5870, then completes his DOT exam two weeks later. Because he only has about 6 weeks of glucose records on insulin, the examiner can qualify him for up to 3 months, but no longer. Once he has 3 months of compliant records and his clinician completes a new MCSA-5870, he can be recertified for up to 12 months.
Does Diabetes Make You Lose Your CDL?
Diabetes doesn't automatically cancel your CDL — the immediate issue is your DOT medical certification. Without a current medical certification, you can't legally operate a commercial motor vehicle that requires one.
For drivers required to maintain medical certification, the state updates the driver's medical status to "not-certified" when the certification expires or becomes invalid. The state must then begin downgrade procedures, and the CDL downgrade must be completed within 60 days unless the driver becomes medically certified again or changes to an eligible self-certification category.
For many drivers, a lapse is fixable — address the medical or paperwork issue and complete a new qualifying examination before the downgrade process is completed.
What Happens If You Don't Pass Because of Diabetes?
Get evaluated by your treating clinician, get a new form, and return for a new exam within 45 days.
At the examiner's discretion, you may qualify for a certificate of up to 3 months while you build 3 months of electronic glucose records.
Work with your treating clinician to stabilize your treatment, then return for a new exam.
Severe non-proliferative or proliferative retinopathy is a permanent disqualification under the insulin standard.
If you disagree with an examiner's decision, FMCSA's handbook notes that the rules don't prohibit you from getting a second exam from another certified medical examiner — but you're expected to give both examiners the same medical information.
Frequently Asked Questions
Can you get a DOT medical card with diabetes?
Yes. Diabetes alone is not disqualifying. Drivers who don't use insulin have no diabetes-specific federal standard, and insulin-treated drivers can be certified under 49 CFR 391.46.
Can you drive a truck if you take insulin?
Yes. Since FMCSA's 2018 rule, insulin-treated drivers can be certified by a medical examiner without a federal exemption, provided they have a completed MCSA-5870 from their treating clinician, a stable insulin regimen, and properly controlled diabetes.
Do I still need a diabetes exemption to drive interstate on insulin?
No. The Federal Diabetes Exemption Program ended when the insulin standard in 49 CFR 391.46 took its place. You qualify through your treating clinician's MCSA-5870 and the DOT exam instead.
What is the MCSA-5870?
It's the Insulin-Treated Diabetes Mellitus Assessment Form. Your treating clinician — the provider who manages your diabetes and prescribes your insulin — completes, signs, and dates it before each DOT exam. Your exam must happen within 45 days of that signature.
How long is a DOT medical card if you're on insulin?
A maximum of 12 months. If you don't yet have 3 months of compliant electronic glucose records while on insulin, the examiner may qualify you for up to 3 months, but no longer.
How long is a DOT medical card with diabetes if I don't use insulin?
There's no diabetes-specific limit, so the general maximum of 2 years applies. The examiner can certify you for less if they want to monitor you more closely.
What A1C do you need to pass a DOT physical?
Federal rules don't set a specific A1C number. Some examiners use their own rule of thumb, and your A1C may be one factor they consider, but no federal regulation sets a pass/fail A1C value.
Is metformin disqualifying for a DOT physical?
No. Oral diabetes medication isn't disqualifying by itself. The examiner looks at how well your diabetes is controlled, any complications, and medication side effects.
Do I need glucose logs for my DOT physical?
If you use insulin, yes — you must keep records on an electronic glucometer that stores all readings with the date and time and can be downloaded, and provide them to your treating clinician at the evaluation. You need at least 3 months of these records for a certificate of up to 12 months.
Can I use a continuous glucose monitor (CGM) for DOT records?
The rule describes the device requirements — it must store all readings, record the date and time, and allow electronic download — rather than naming specific devices. Ask your treating clinician and examiner whether your device's records meet those requirements before your exam.
What counts as a severe hypoglycemic episode for DOT purposes?
One that requires the assistance of others, or results in loss of consciousness, seizure, or coma.
What happens if I have a severe low while I'm certified?
If you use insulin, you must stop operating a CMV and be evaluated by a treating clinician as soon as reasonably practicable. You can't drive a CMV again until the clinician determines the cause has been addressed, confirms a stable regimen and proper control, and completes a new MCSA-5870.
Does diabetic retinopathy disqualify you from a DOT physical?
For insulin-treated drivers, severe non-proliferative or proliferative diabetic retinopathy is permanently disqualifying. FMCSA's handbook states that rule does not apply to non-insulin-treated diabetes or to retinopathy generally — those drivers are evaluated under the vision standard and other standards.
Can I get a second opinion if I fail for diabetes?
Yes. FMCSA's rules don't prohibit a second exam from another certified medical examiner, but you're expected to provide the same medical information to both.
Does diabetes affect my CDL or just my medical card?
It affects your medical certificate first. Without a current medical card you can't legally operate a CMV that requires one — and if your medical status stays "not certified," your state must downgrade your CDL within 60 days.
Sources
- 49 CFR 391.41(b)(3) — Physical qualifications for drivers (diabetes mellitus)
- 49 CFR 391.46 — Physical qualification standards for an individual with diabetes mellitus treated with insulin for control
- 49 CFR 391.45 — Persons who must be medically examined and certified
- 49 CFR 383.73(o) — State procedures for medical certification status and CDL downgrade
- FMCSA Medical Examiner's Handbook, 2024 Edition
- FMCSA — Insulin-Treated Diabetes Mellitus Assessment Form, MCSA-5870
- FMCSA — Non-Insulin-Treated Diabetes Mellitus Assessment Form, MCSA-5872 (Optional)
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