Former President Donald Trump said he'd "absolutely" be up for adding Elon Musk to his cabinet though he believes Musk will serve more as a consultant.
The Trump II cabinet so far: Tulsi Gabbard, RFK, Jr. and Elon Musk.
The Cabinet does not have any collective executive powers or functions of its own, and no votes need to be taken. There are 26 members: the vice president, 15 department heads, and 10 Cabinet-level officials, all except two of whom require Senate confirmation. During Cabinet meetings, the members sit in the order in which their respective department was created, with the earliest being closest to the president and the newest farthest away.
https://en.m.wikipedia.org/wiki/Cabinet_of_the_United_States