Subject to subsection (c) of this section, a policy, contract, or certificate described in § 15–701(a) of this subtitle may provide for reimbursement under § 15–701(a) of this subtitle for usual, customary, and reasonable charges for services rendered by a dietitian or nutritionist licensed under the Health Occupations Article if a licensed physician determines that the services are medically necessary for the treatment of cardiovascular disease, diabetes, prediabetes, obesity, malnutrition, cancer, cerebral vascular disease, or kidney disease. Application of this subsection is limited to six visits with a dietitian or nutritionist during a 12–month period for each condition described in paragraph (1) of this subsection and to services for the treatment of obesity only if provided in conjunction with the treatment of a condition described in paragraph (1) of this subsection. This section does not require a policy, contract, or certificate described in § 15–701(a) of this subtitle to provide coverage for services rendered by a nutritionist or dietitian. If a service covered under a policy, contract, or certificate described in § 15–701(a) of this subtitle is provided to a hospital patient by a dietitian or nutritionist: the usual, customary, and reasonable charges of the dietitian or nutritionist shall be included in the patient’s hospital charges; and the dietitian or nutritionist may not bill the patient separately for the service.