Maryland Code, Insurance § 15-837

(1) insurers and nonprofit health service plans that provide hospital, medical, or surgical benefits to individuals or groups on an expense-incurred basis under health insurance policies or contracts that are issued or delivered in the State; and

(2) health maintenance organizations that provide hospital, medical, or surgical benefits to individuals or groups under contracts that are issued or delivered in the State.

(c)(1) Subject to paragraph (2) of this subsection, the coverage required under this section may be subject to a copayment or coinsurance requirement or deductible that an entity subject to this section imposes for similar coverages under the same policy or contract.

(2) The copayment or coinsurance requirement or deductible imposed under paragraph (1) of this subsection may not be greater than the copayment or coinsurance requirement or deductible imposed by the entity for similar coverages.