“ A participant who is separated involuntarily from service, except by removal for cause on charges of misconduct or delinquency, is entitled to an annuity only if the participant has not declined a reasonable offer of another position for which he or she is qualified, which is not lower than two grades below his or her current position and which is in the same commuting area. Voluntary early retirements will be permitted only if a major reorganization, reduction in force, or transfer of function will result in a significant number of participants being separated or immediately reduced in pay. ”

“ If the annuitant receiving disability retirement annuity is restored to earning capacity, before becoming sixty years of age, payment of the annuity terminates on reemployment by the Government or 180 days after the end of the calendar year in which earning capacity is restored, whichever is earlier. Earning capacity is restored if in any calendar year the income of the annuitant from wages or self-employment or both equals at least 80 per centum of the current rate of pay of the position occupied at the time of retirement.". ”

“ Each participant who has performed military service before the date of separation on which the entitlement to any annuity under this section is based may pay, in accordance with rules issued by the Director, to the Agency an amount equal to 7 percent of the amount of basic pay paid under section 204 of Title 37 of the United States Code to the participant for each period of military service after December 1956. ”