Md. Code, Insurance § 15–502

(a) This section applies to each individual or group policy or certificate of health insurance or automobile insurance that is:

(1) delivered or issued for delivery in the State by an insurer or nonprofit health service plan; and

(2) issued, renewed, amended, or reissued on or after July 1, 1978.

(b) A policy or certificate subject to this section that provides or pays for health care benefits may not contain a provision that denies or reduces benefits because services are rendered to a policyholder, certificate holder, or beneficiary who is eligible for or receives medical assistance under § 15-103 of the Health - General Article.