; and (B) by an out-of-network health care professional; or (3) additional health care services required in the case of an enrollee who initially enters a hospital through the emergency room for emergency services, and then receives nonemergency services from an out-of-network health care professional or at an out-of-network hospital or facility after the enrollee has been stabilized (as defined in section 2719A(b)(2)(C)), as determined by the treating physician. Paragraph (3) shall not apply in the case of an enrollee who is stabilized and able to travel in nonmedical transport, and the enrollee (or designee of the enrollee where the enrollee is not able to comprehend the information to be provided or make related decisions) has been provided with clear, written notification that the professional or facility is an out-of-network health care professional or facility, has been given a cost estimate for services provided by the out-of-network professional or facility, and has assumed, in writing, full responsibility for out-of-pocket costs associated with such out-of-network care. (b) Balance bill In subsection (a), the term balance bill refers to a claim for payment for services provided to an enrollee that is in an amount equal to the difference between the actual amount charged with respect to services or care described in subsection (a) and the expected in-network cost-sharing required by the enrollee under the plan or coverage involved. (c) Prohibition on balance billing (1) Prohibition (A) In general A group health plan, a health insurance issuer in connection with group or individual health insurance coverage, or a health care provider shall not engage in balance billing practices prohibited under this section. (B) Application of provisions Subparagraph (A) shall apply— (i) to all services provided at hospitals, emergency rooms, State-accredited free-standing emergency departments, hospital outpatient departments, and ambulatory surgery centers