; and (iii) by redesignating the second subsection (c) as subsection (d); (B) in section 276(b)(4) ( 8 U.S.C. 1326(b)(4) ), by striking section 241(a)(4)(B) and inserting section 237(a)(4)(B) ; and (C) in section 501(1) ( 8 U.S.C. 1531(1) ), by striking section 241(a)(4)(B) and inserting section 237(a)(4)(B) . 10. Prohibition on solitary confinement (a) In general An individual in the custody of the Department may not be placed in solitary confinement. (b) Definition of solitary confinement In this section, the term solitary confinement means— (1) in the case of an individual who is older than 21 years of age, the state of being confined to the individual’s cell, alone or with a cellmate, for more than 22 hours during a 24-hour period, with very limited out-of-cell time and severely restricted activity, movement, and social interaction whether pursuant to disciplinary, administrative, or classification action; and (2) in the case of an individual who is 21 years of age or younger, involuntary confinement alone in a cell, room, or other area for a period greater than 3 hours.