Md. Code Regs. 11.22.04.01
The standards, requirements, and procedures set forth in this chapter are applicable to equipment originally installed by the manufacturer or required by federal or State law or regulation on any vehicle registered as a Class G (freight trailer) vehicle under the provisions of Transportation Article, Title 13, Annotated Code of Maryland, or any freight trailer or semitrailer owned by this State or any political subdivision of this State. Compliance with these minimum requirements may not be sufficient for the equipment to remain in compliance for 12 months or 25,000 miles, whichever occurs first. Therefore, more frequent maintenance, service, and repair as deemed necessary by the owner is permitted and recommended.
Md. Code Regs. 11.22.04.01