; (B) in paragraph (21), by striking the period at the end and inserting ; or ; and (C) by adding at the end the following new paragraph: (22) Service performed by members of Indian tribal councils as tribal council members in the employ of a tribal organization, except that this paragraph shall not apply in the case of service included under an agreement under section 218A. . (2) Internal Revenue Code of 1986 The Internal Revenue Code of 1986 is amended— (A) in section 3121(b)— (i) in paragraph (20), by striking or at the end; (ii) in paragraph (21), by striking the period at the end and inserting ; or ; and (iii) by adding at the end the following new paragraph: (22) service performed by members of Indian tribal councils as tribal council members in the employ of a tribal organization, except that this paragraph shall not apply in the case of service included under an agreement under section 218A of the Social Security Act. ; and (B) in section 3121(d)(4), by inserting or 218A after section 218 . (c) Rule of construction Nothing in this Act or the amendments made by this Act shall be construed to affect application of any Federal income tax withholding requirements under the Internal Revenue Code of 1986.