If the disability is partial, the United States shall pay the employee during the disability monthly monetary compensation equal to 66⅔ percent of the difference between his monthly pay and his monthly wage-earning capacity after the beginning of the partial disability, which is known as his basic compensation for partial disability.
(b) The Secretary of Labor may require a partially disabled employee to report his earnings from employment or self-employment, by affidavit or otherwise, in the manner and at the times the Secretary specifies. The employee shall include in the affidavit or report the value of housing, board, lodging, and other advantages which are part of his earnings in employment or self-employment and which can be estimated in money. An employee who—
forfeits his right to compensation with respect to any period for which the affidavit or report was required. Compensation forfeited under this subsection, if already paid, shall be recovered by a deduction from the compensation payable to the employee or otherwise recovered under section 8129 of this title, unless recovery is waived under that section.
(c) A partially disabled employee who—
is not entitled to compensation.
(Pub. L. 89–554, Sept. 6, 1966, 80 Stat. 536.)