What a Class CM1 License Lets You Drive
A Class CM1 license is California's restricted commercial license for drivers who operate motorhomes, mobile homes, or recreational vehicles (RVs) that meet specific weight and configuration requirements. It sits between a regular Class C license and a full Class B commercial license, designed for people who drive their own RV but do not operate commercial vehicles for hire.
The CM1 class covers motorhomes with a gross vehicle weight rating (GVWR) between 10,001 and 26,000 pounds. If your RV weighs more than 26,000 pounds, you need a Class B commercial license instead. If it weighs less than 10,001 pounds, a regular Class C license is sufficient.
You can also tow a trailer with a CM1 license, as long as the combined weight of the motorhome and trailer does not exceed the vehicle's towing capacity and does not push you into Class B territory. The key is that you are driving for personal use, not operating a commercial vehicle service.
Key Takeaways
- A Class CM1 license covers motorhomes weighing between 10,001 and 26,000 pounds GVWR for personal use only.
- You must pass a written knowledge test, a behind-the-wheel driving test, and a medical examination before the DMV issues a CM1 license.
- The written test covers RV-specific rules, air brake systems, and safe operation of larger vehicles.
- Your CM1 license is valid for five years in California, the same as a standard Class C license.
- If you drive a motorhome heavier than 26,000 pounds GVWR, you need a Class B commercial license, which requires additional endorsements and testing.
Who Needs a Class CM1 License
You need a CM1 license if you own or regularly operate a motorhome in the weight range above and plan to drive it on California roads. The DMV does not require a CM1 for occasional drivers or passengers, only for the person behind the wheel.
If you currently hold a Class C license and own an RV in the CM1 weight range, you are driving illegally. The DMV can cite you for operating a vehicle that requires a higher class of license. Upgrading to CM1 is straightforward and takes less time than obtaining a commercial Class B license.
You do not need a CM1 if your motorhome weighs under 10,001 pounds GVWR — your Class C license covers it. You also do not need it if you are a passenger or if someone else with a valid CM1 or Class B license is driving.
Testing Requirements for Class CM1
California requires three separate tests before you can receive a CM1 license: a written knowledge test, a behind-the-wheel driving test, and a medical examination.
The written test covers motorhome operation, vehicle weight and dimensions, air brake systems, and safe driving practices for larger vehicles. You answer 36 questions and must score at least 30 correct (83 percent). The test is offered in multiple languages at DMV offices. You can study using the California Commercial Driver Handbook, available free on the DMV website.
The behind-the-wheel test takes place in your motorhome or a similar vehicle provided by the DMV. The examiner watches you perform basic maneuvers, lane changes, backing, and parking. You must demonstrate safe control of the vehicle and knowledge of traffic laws. The test typically lasts 30 to 45 minutes.
The medical examination is performed by a licensed physician or certified medical examiner. The DMV provides a form (DL 51) that the doctor completes after checking your vision, hearing, and general health. You pay the doctor's fee directly — the DMV does not cover it. Most exams cost between $50 and $150.
How to Get Your Class CM1 License
Start by visiting your local DMV office or the DMV website to request a CM1 process packet. You will need to bring proof of identity, proof of California residency, and your current driver license. If you do not have a current license, bring a birth certificate or passport instead.
Schedule your medical examination first. You cannot take the written or driving test without a completed DL 51 form. Once you have the form, bring it to the DMV along with your process and identification documents.
Take the written test at the DMV. If you pass, you receive a permit that allows you to practice driving your motorhome. You must have a licensed driver with a valid CM1 or Class B license in the vehicle with you during practice.
Schedule your behind-the-wheel test once you feel ready. Bring your motorhome, your permit, and your identification. If you pass, the DMV issues your Class CM1 license on the spot. If you fail, you can retake it after waiting one day.
Costs and Timeline
The DMV charges a fee to upgrade from Class C to CM1. As of 2024, the upgrade fee is $35, though this varies and you should confirm the current amount with your local DMV office. The medical examination fee is separate and paid directly to the doctor or clinic, typically $50 to $150.
The entire process usually takes two to four weeks from start to finish, depending on how quickly you schedule your medical exam and tests. Some DMV offices have longer wait times for behind-the-wheel tests, so call ahead to check availability in your area.
Your CM1 license is valid for five years from the date of issue. You renew it the same way you renew a Class C license — by mail, online, or in person at the DMV — unless your medical status changes or the DMV requires an in-person renewal.
Class CM1 Restrictions and Rules
A CM1 license is restricted to personal use only. You cannot use it to operate a motorhome for hire, as a tour guide, or as a commercial shuttle service. If you want to drive an RV commercially, you need a Class B commercial license with the appropriate endorsements.
You must obey all traffic laws and weight restrictions that explore to your motorhome. Some California highways and bridges have weight limits or restrictions on large vehicles. Check with the California Department of Transportation (Caltrans) before traveling on unfamiliar routes.
If you accumulate traffic violations or your medical condition changes, the DMV may suspend or revoke your CM1 license. You are also required to report any serious medical conditions — such as seizures, loss of consciousness, or significant vision loss — to the DMV within 10 days.
Class CM1 vs. Class B Commercial License
The main difference is weight and purpose. A CM1 covers motorhomes between 10,001 and 26,000 pounds for personal use. A Class B commercial license covers any vehicle over 26,000 pounds GVWR or any vehicle used for commercial purposes, regardless of weight.
A Class B license requires more extensive testing, including a written test on air brakes and hazardous materials (if applicable), a pre-trip inspection test, and a behind-the-wheel test that is longer and more rigorous than the CM1 test. You may also need additional endorsements depending on what you are driving.
If your motorhome weighs more than 26,000 pounds or you plan to operate it commercially, you must obtain a Class B license instead of CM1. The DMV can advise you on which class applies to your specific vehicle.
Frequently Asked Questions
Can I drive someone else's motorhome with my Class CM1 license?
Yes, as long as the motorhome falls within the CM1 weight range (10,001 to 26,000 pounds GVWR) and you are driving it for personal use, not for hire. Your license is tied to you as a driver, not to a specific vehicle. However, if the motorhome weighs more than 26,000 pounds, you cannot legally drive it without a Class B license.
What happens if I fail the behind-the-wheel test?
You can retake the test after waiting one day. There is no limit to how many times you can retake it, though each attempt may have a fee. Many people pass on their second or third try. The DMV will tell you what you need to improve before your next attempt.
Do I need a CM1 license if I only drive my motorhome once a year?
Yes. The frequency of use does not matter — if you operate a motorhome in the CM1 weight range, you must have the appropriate license. Driving without one is illegal, even if it is infrequent.
Can I upgrade from Class C to CM1 online?
No. You must visit a DMV office in person to explore, take the written test, and schedule your behind-the-wheel test. You can renew a CM1 license online if you meet certain conditions, but the initial upgrade requires an office visit.
What if my motorhome is right at 10,001 pounds — do I need CM1?
Yes. If your motorhome's GVWR is 10,001 pounds or higher, you need a CM1 license. The threshold is 10,001 pounds, not 10,000. Check your vehicle's registration or door placard to confirm the exact GVWR.