Which of the following is NOT a requirement for obtaining a CDL?

To obtain a Commercial Driver's License (CDL), one of the requirements is to hold a valid driver's license. This establishes that the individual already possesses basic driving skills necessary to operate a vehicle safely. Additionally, passing a written test is essential as it ensures that the applicant has the knowledge needed about operating commercial vehicles, including traffic laws and safety regulations. A clean driving record is also a significant factor, as it reflects the applicant's history of safe driving and compliance with traffic laws, which is critical for a role that involves operating larger and potentially more dangerous vehicles.

On the other hand, having a high school diploma is not a specific requirement for obtaining a CDL. While some employers may prefer or require a diploma or equivalent educational credential, it is not mandated by the Department of Transportation or state licensing authorities for the licensing process itself. Therefore, a high school diploma is not necessary to pursue obtaining a CDL.