Md. Code, Insurance § 27–913

(a) This section applies to:

(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.

(b) Unless otherwise provided by law, an entity subject to this section may not make benefits under a policy or contract issued or delivered by the entity in the State for the treatment of a specified disease or diagnosis subject to different copayment amounts, coinsurance, deductibles, annual maximum limits, or lifetime maximum limits than those that apply to all other diseases covered under the policy or contract.