podiatric or optometry functions in the State, territory, or possession in which the individual performs such services, (iii) a physician, as defined in section 1861(r) of the Social Security Act Section ( 42 U.S.C. 1395x(r) ) or section 8101(2) of title 5, United States Code, or (iv) an advanced care practitioner, and (C) the services described in subparagraph (A) performed by the individual are performed pursuant to a written contract and such contract provides that the individual will not be treated as an employee with respect to such services for purposes of this subtitle. (2) Advanced care practitioner The term advanced care practitioner means a nurse practitioner, physician’s assistant, or certified registered nurse anesthetist. . (b) Clerical amendment The table of sections of chapter 25 of such Code is amended by adding at the end the following new item: Sec. 3513. Treatment of locum tenens physicians and advanced care practitioners. . (c) Effective date The amendments made by this section shall apply to wages for services performed after the date of the enactment of this Act.