What You Need to Do to Add Tanker and Hazmat to Your CDL
A tanker endorsement (T) and hazmat endorsement (H) are separate additions to your CDL, but you can test for both at the same time. You do not need one before getting the other. To add them, you pass written tests at your state's DMV or testing facility — one test for tanker knowledge, one for hazmat knowledge — and you pay the associated fees. Most states charge between $10 and $50 per endorsement test, though the exact amount varies by state.
Before you can test, your CDL must already be valid and in your possession. You cannot add endorsements to a permit or a suspended license. If you are upgrading from a regular driver's license to a CDL for the first time, you must pass your CDL written test and skills test first, then return to add tanker and hazmat.
Key Takeaways
- Tanker and hazmat are two separate endorsements; you test for each one independently, but can take both tests on the same visit to the DMV.
- You must have a valid CDL before you can add endorsements; you cannot add them to a permit or suspended license.
- Each endorsement requires a written knowledge test at your state's DMV or approved testing location; there is no skills test component.
- Hazmat endorsement requires a federal background check and fingerprinting through the Transportation Security Administration (TSA), which adds time and cost beyond the written test.
- Study materials for both tests are available free from your state's CDL manual; many states also offer practice tests online.
Why Tanker and Hazmat Are Separate Endorsements
The tanker endorsement (T) covers the rules for transporting liquids and gases in bulk — how to handle surge and slosh, how to brake safely with a full tank, how to position your vehicle, and what to do if your load shifts. The hazmat endorsement (H) covers the rules for transporting any hazardous material — how to label, placard, and document shipments, what to do in an emergency, and which materials you can and cannot carry together.
A driver can have tanker without hazmat (hauling non-hazardous liquids like water or milk), or hazmat without tanker (hauling hazardous solids or small quantities of liquids in boxes). Many drivers need both because they haul hazardous liquids — gasoline, propane, or chemicals — which requires both endorsements on the same license.
The Written Tests and What They Cover
The tanker test is typically 20 questions on your state's CDL exam. It covers tank vehicle dynamics (how a full tank behaves differently from a partial one), safe driving practices specific to tankers, emergency procedures, and equipment inspection. You must score at least 80 percent to pass, which is the standard for all CDL knowledge tests.
The hazmat test is also typically 20 to 30 questions, depending on your state. It covers the hazmat classification system (how materials are categorized by danger type), shipping papers and documentation, placarding and labeling, loading and unloading rules, and emergency response. You must also score at least 80 percent. Some states offer the hazmat test only in English, even if other CDL tests are available in other languages.
Both tests are closed-book. You cannot bring notes, your CDL manual, or any reference material into the testing room. You study beforehand using your state's CDL manual, which is free and available online or in print from your DMV.
The Hazmat Background Check and TSA Fingerprinting
If you pass the hazmat written test, you do not automatically get the endorsement. The Transportation Security Administration (TSA) must conduct a federal background check and collect your fingerprints before your state can issue the endorsement. This step is required by federal law for anyone who will transport hazardous materials.
Your state's DMV will direct you to a fingerprinting location — usually a local police station, sheriff's office, or a private fingerprinting service contracted by the state. You pay a fee for fingerprinting, which ranges from $10 to $50 depending on your state and location. The TSA then processes your background check, which typically takes one to two weeks but can take longer if the TSA needs to investigate something in your record.
If you have certain criminal convictions, disqualifying mental health commitments, or immigration violations, the TSA will deny your hazmat endorsement. The TSA publishes a list of disqualifying offenses on its website. If you are unsure whether your record will disqualify you, contact your state's DMV before you pay for the fingerprinting and test.
How to Prepare for Both Tests
Start with your state's official CDL manual, which contains all the material covered on both tests. Most states publish this manual free online as a PDF; you can also request a printed copy at your DMV. Read the sections on tanker vehicles and hazmat materials carefully, because both tests pull directly from this material.
Many states offer free practice tests online through their DMV website. Take these tests multiple times until you score 90 percent or higher consistently. Practice tests help you identify weak areas and get used to the question format and pacing. Some third-party websites also offer CDL practice tests, but stick to materials based on your state's manual to avoid studying information that does not explore in your state.
Study groups and CDL training schools can also help, though they are not required. If you are already enrolled in a CDL training program, your instructor will cover tanker and hazmat material as part of the curriculum. If you are testing on your own, the free state manual and practice tests are usually sufficient.
Testing Day and What Happens Next
Schedule your tests at your state's DMV or at an approved third-party testing facility. Some states allow you to test at private locations; others require you to test at the DMV. Call ahead or check your state's DMV website to find out where you can test and whether you need an appointment.
Bring your valid CDL, a government-issued photo ID, and any documents your state requires (check your DMV website beforehand). Arrive early. You will take the tanker test first, then the hazmat test, or vice versa — the order does not matter. Each test takes 20 to 30 minutes. If you pass both, you will receive a receipt or temporary document showing you passed.
Your state will then issue an updated CDL with both endorsements added. This usually happens within one to two weeks if you are only adding tanker. If you are adding hazmat, the timeline depends on how long the TSA background check takes — typically one to two weeks, but sometimes longer. Your state may issue a temporary hazmat endorsement while the background check is pending, or you may have to wait for the final clearance before the endorsement appears on your license.
Costs and Fees by State
The total cost to add tanker and hazmat varies by state. Tanker endorsement testing typically costs $10 to $30. Hazmat endorsement testing typically costs $10 to $30. Fingerprinting for the TSA background check costs $10 to $50. Some states bundle these fees; others charge them separately. A few states waive the hazmat test fee if you are already a CDL holder, but most do not.
Contact your state's DMV directly or visit their website to find the exact fees for your state. Fees can change, and some states offer discounts for military veterans or other groups. If cost is a barrier, ask whether your employer will cover the testing and fingerprinting fees — many trucking companies do, especially if they need drivers with these endorsements.
Frequently Asked Questions
Can I test for tanker and hazmat on the same day?
Yes. You can take both written tests at the same visit to your DMV or testing facility. You do not have to pass one before taking the other. However, if you are adding hazmat, the TSA background check happens after you pass the test, so the endorsement will not appear on your license until that clears.
What disqualifies you from getting a hazmat endorsement?
The TSA will deny hazmat based on certain felony convictions (especially those involving explosives, weapons, or transportation crimes), disqualifying mental health commitments, immigration violations, and some other factors. The TSA publishes the full list on its website. If you have questions about your specific record, contact your state's DMV before testing.
Do I need a medical certificate to add tanker or hazmat?
No. You need a valid medical certificate to hold any CDL, but adding endorsements does not require a new medical exam. If your CDL is already valid, your medical certificate is already current.
How long does the TSA background check take for hazmat?
Typically one to two weeks, but it can take longer if the TSA needs additional time to review your record. During this time, you cannot legally transport hazardous materials. Some states issue a temporary hazmat endorsement while you wait; others require you to wait for final clearance.
Can I renew my tanker and hazmat endorsements at the same time as my CDL?
Yes. Tanker and hazmat endorsements renew on the same schedule as your CDL. When you renew your CDL, you will retake the tanker and hazmat written tests (or in some states, answer a shorter renewal test). You will also go through the TSA background check again for hazmat. Plan for the same timeline as your initial endorsement.