5 USC 8440 – Tax treatment of the Thrift Savings Fund
(a) For purposes of the Internal Revenue Code of 1986—
(1) the Thrift Savings Fund shall be treated as a trust described in section 401(a) of such Code which is exempt from taxation under section 501(a) of such Code;
(2) any contribution to, or distribution from, the Thrift Savings Fund shall be treated in the same manner as contributions to or distributions from such a trust; and
(3) subject to section 401(k)(4)(B) of such Code and any dollar limitation on the application of section 402(a)(8) of such Code, contributions to the Thrift Savings Fund shall not be treated as distributed or made available to an employee or Member nor as a contribution made to the Fund by an employee or Member merely because the employee or Member has, under the provisions of this subchapter and section 8351 of this title, an election whether the contribution will be made to the Thrift Savings Fund or received by the employee or Member in cash.
(b)
(c) Subsection (a) shall not be construed to provide that any amount of the employee’s or Member’s basic pay which is contributed to the Thrift Savings Fund shall not be included in the term “wages” for the purposes of section 209 of the Social Security Act or section 3121(a) of the Internal Revenue Code of 1986.