1. Short title This Act may be cited as Appointments Clause Enforcement Act of 2020 . 2. Modifications to Federal Vacancies Reform Act of 1998 (a) Acting officer (1) First assistants Section 3345(a) of title 5, United States Code, is amended— (A) in paragraph (1), by adding at the end before the semi-colon the following: , but only if the individual serving in the position of first assistant has occupied such position for the period of 120 days immediately preceding the date of the death, resignation, or beginning of inability to serve (as the case may be) ; and (B) by adding at the end the following: (d) (1) For purposes of this section, beginning on the date that is 180 days after the date of enactment of the Appointments Clause Enforcement Act of 2020, a position shall be considered to be the first assistant to the office with respect to which a vacancy occurs only if such position has been designated by law, rule, or regulation as the first assistant position. (2) With respect to any office to which this section and sections 3346, 3347, 3349, 3349a, 3349b, 3349c, and 3349d apply that is established after the date that is 180 days after the date of enactment of this subsection that does not have a first assistant position designated by law, the head of the Executive agency at which such office is located shall designate a first assistant position not later than the date that is 60 days after such date of establishment. . (2) Presidential appointments Section 3345(a) of title 5, United States Code, as amended by paragraph (1), is further amended— (A) in paragraph (2), by striking who serves in an office and inserting who serves in an office within the same agency at which the vacancy occurs for the period of 120 days immediately preceding the date on which such vacancy occurs ; and (B) in paragraph (3), (i) by striking and at the end of subparagraph (A)