5 U.S. Code § 7513 - Cause and procedure
(a) Under regulations prescribed by the Office of Personnel Management, an agency may take an action covered by this subchapter against an employee only for such cause as will promote the efficiency of the service.
(b) An employee against whom an action is proposed is entitled to—
(1) at least 30 days’ advance written notice, unless there is reasonable cause to believe the employee has committed a crime for which a sentence of imprisonment may be imposed, stating the specific reasons for the proposed action;
(2) a reasonable time, but not less than 7 days, to answer orally and in writing and to furnish affidavits and other documentary evidence in support of the answer;
(c) An agency may provide, by regulation, for a hearing which may be in lieu of or in addition to the opportunity to answer provided under subsection (b)(2) of this section.
(d) An employee against whom an action is taken under this section is entitled to appeal to the Merit Systems Protection Board under section 7701 of this title.
(e) Copies of the notice of proposed action, the answer of the employee when written, a summary thereof when made orally, the notice of decision and reasons therefor, and any order effecting an action covered by this subchapter, together with any supporting material, shall be maintained by the agency and shall be furnished to the Board upon its request and to the employee affected upon the employee’s request.