Adding an endorsement to your CDL qualifies you for freight or vehicle types that fewer drivers can legally haul or operate. That smaller qualified pool is what drives the pay premium. Carriers who need hazmat-cleared drivers, tank vehicle operators, or doubles-capable drivers pay more precisely because they have fewer options for filling those seats.The endorsements worth pursuing for pay purposes are well established. What most guides about them get wrong is treating the process to obtain each one as roughly equivalent. It is not. Some endorsements require federally mandated training from a registered provider, a TSA background check, and a waiting period before your DMV will issue the credential. Others require nothing beyond showing up at the DMV and passing a written test. Knowing the difference before you decide which endorsement to pursue changes both the timeline and the cost calculation.The Endorsement Codes on Your CDLYour CDL displays endorsements as single-letter codes. The