Md. Code Ann., Transp. § 14-101
(a) This title does not apply to the following:
(2) A self-propelled invalid:
(b) This title does not apply to the following unless a certificate of title has been issued for them under Title 13 of this article:
Added by Acts 1977, c. 14, § 2, eff. July 1, 1977.
Formerly Art. 66 ½, § 4-101.