Maryland Code, Health-General § 15-102.5

(a) Subject to § 15-103(f) of this subtitle, a health maintenance organization that requires its panel providers to participate in a managed care organization shall establish a mechanism, subject to review by the Secretary, which provides for equitable distribution of enrollees and which ensures that a provider will not be assigned a disproportionate number of enrollees.

(b) Nothing in this section may be interpreted as prohibiting a provider from voluntarily accepting additional enrollees.