Section 4. A health maintenance contract shall provide coverage for:

(a) pregnant women, infants and children as set forth in section 47C of chapter 175;

(b) cardiac rehabilitation as set forth in section 47D of chapter 175;

(c) prenatal care, childbirth and postpartum care as set forth in section 47F of chapter 175;

(d) cytologic screening and mammographic examination as set forth in section 47G of chapter 175;

(e) diagnosis and treatment of infertility as set forth in section 47H of chapter 175; and

(f) services rendered by a certified registered nurse anesthetist or nurse practitioner as set forth in section 47Q of chapter 175, subject to the terms of a negotiated agreement between the health maintenance organization and the provider of health care services.

The dependent coverage of any such policy shall also provide coverage for medically necessary early intervention services delivered by certified early intervention specialists, as defined in the early intervention operational standards by the department of public health and in accordance with applicable certification requirements. Such medically necessary services shall be provided by early intervention specialists who are working in early intervention programs certified by the department of public health, as provided in sections 1 and 2 of chapter 111G, for children from birth until their third birthday. Reimbursement of costs for such services shall be part of a basic benefits package offered by the insurer or a third party and shall not require co-payments, coinsurance or deductibles; provided, however, that co-payments, coinsurance or deductibles shall be required if the applicable plan is governed by the Federal Internal Revenue Code and would lose its tax-exempt status as a result of the prohibition on co-payments, coinsurance or deductibles for these services.