(ii) Guidance on development of prospective payment system for testing under State demonstration programs (I) In general The Secretary shall issue guidance for States participating in a demonstration program conducted under paragraph (3) to establish a prospective payment system that shall only apply to freestanding birth center services that meet the criteria established under clause (i) furnished by a freestanding birth center participating in such demonstration program. (II) Requirements The guidance issued by the Secretary under subclause (I) shall, to the greatest extent practicable, provide for— (aa) partial facility payment based on units in the case that a pregnant woman is admitted in labor and then needs to be transferred to the hospital in labor before the birth of the baby