D.C. Mun. Regs. tit. 18, § 1302
1302.1 A commercial driver's instruction license shall be issued only to an individual who holds a valid noncommercial driver's license or a valid commercial driver's license if applying to operate commercial vehicles in a group or endorsement other than the group or endorsement that he or she is authorized to operate.
1302.2 A commercial driver's instruction license shall be issued only to an individual who is twenty-one (21) years of age or older, except that a commercial driver's instruction license may be issued to a person who is at least 18 years of age and has at least 2 years drivers experience; provided, that a commercial driver's instruction license issued to a person who is less than 21 years of age shall not be valid for:
(a) Operation of a school bus;
(b) Operation of a vehicle designed to transport 16 or more people, including the driver;
(c) Operation of a vehicle that is more than 26,001 pounds;
(d) Transportation of hazardous material; or
(e) Commercial interstate operation in accordance with the minimum federal standards.
1302.3 A commercial driver's instruction license shall only be issued to persons who have successfully passed the appropriate knowledge tests with at least an eighty percent (80%) score.
1302.4 A commercial driver's instruction license shall be issued only to persons who meet the physical qualifications and examinations provided in § 1327.
1302.5 A holder of a commercial driver's instruction license shall not operate a commercial vehicle unless accompanied by a driver who has been licensed for at least one (1) year to drive the type and class of vehicle being used.
1302.6 A holder of a commercial driver's instruction license shall not operate a commercial vehicle unless accompanied by someone who is fit and capable of exercising physical control over the vehicle and who is occupying a seat beside the driver.
1302.7 The commercial driver's instruction license shall be valid for a limited period of not less than thirty (30) days.
1302.8 These requirements shall not apply to Class "D," Class "M" and Class "N" driver's licenses.
SOURCE: Final Rulemaking published at 51 DCR 10913 (November 26, 2004); Final Rulemaking published at 53 DCR 2206 (March 24, 2006); as amended by the Commercial Driver's License Minimum Age Requirement Amendment Act of 2010, September 24, 2010 (D.C. Law 18-220), at 57 DCR 5588 (July 2, 2010).