A participant who has become disabled shall, upon the participant’s own application or upon order of the Director, be retired on an annuity computed under subsection (b).
A claim may be allowed under this section only if the application is submitted before the participant is separated from the Agency or within one year thereafter.
The time limitation may be waived by the Director for a participant who, at the date of separation from the Agency or within one year thereafter, is mentally incompetent, if the application is filed with the Agency within one year from the date of restoration of the participant to competency or the appointment of a fiduciary, whichever is earlier.
Except as provided in paragraph (2), an annuity payable under subsection (a) shall be computed under section 2031(a) of this title. However, if the disabled or incapacitated participant has less than 20 years of service credit toward retirement under the system at the time of retirement, the annuity shall be computed on the assumption that the participant has had 20 years of service, but the additional service credit that may accrue to a participant under this paragraph may not exceed the difference between the participant’s age at the time of retirement and age 60.
If a participant retiring under this section is receiving retired pay or retainer pay for military service (except that specified in section 2082(e)(3) of this title) or Department of Veterans Affairs compensation or pension in lieu of such retired or retainer pay, the annuity of that participant shall be computed under section 2031(a) of this title, excluding credit for such military service from that computation. If the amount of the annuity so computed, plus the retired or retainer pay which is received, or which would be received but for the application of the limitation in section 5532  of title 5, or the Department of Veterans Affairs compensation or pension in lieu of such retired or retainer pay, is less than the annuity that would be payable under this section in the absence of the previous sentence, an amount equal to the difference shall be added to the annuity payable under section 2031(a) of this title.
Unless the disability is permanent, like examinations shall be made annually until the annuitant becomes age 60. If the Director determines on the basis of the advice of one or more duly qualified physicians or surgeons conducting such examinations that an annuitant has recovered to the extent that the annuitant can return to duty, the annuitant may apply for reinstatement or reappointment in the Agency within one year from the date the annuitant’s recovery is determined.
Upon application, the Director may reinstate any such recovered disability annuitant in the grade held at time of retirement, or the Director may, taking into consideration the age, qualifications, and experience of such annuitant, and the present grade of the annuitant’s contemporaries in the Agency, appoint the annuitant to a grade higher than the one held before retirement.
Payment of the annuity shall continue until a date one year after the date of examination showing recovery or until the date of reinstatement or reappointment in the Agency, whichever is earlier.
Fees for examinations under this subsection, together with reasonable traveling and other expenses incurred in order to submit to examination, may be paid out of the fund.
If the annuitant fails to submit to examination as required under this section, payment of the annuity shall be suspended until continuance of the disability is satisfactorily established.
If the annuitant receiving a disability retirement annuity is restored to earning capacity before becoming age 60, 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 shall be considered to be restored if in any calendar year the income of the annuitant from wages or self-employment, or both, equals at least 80 percent of the current rate of pay for the grade and step the annuitant held at the time of retirement.
If a recovered or restored disability annuitant whose annuity is discontinued is for any reason not reinstated or reappointed in the Agency, the annuitant shall be considered, except for service credit, to have been separated within the meaning of section 2054 of this title as of the date of termination of the disability annuity.
After such termination, the recovered or restored annuitant shall be entitled to the benefits of section 2054 or 2071(a) of this title, except that the annuitant may elect voluntary retirement under section 2053 of this title, if qualified thereunder, or may be placed by the Director in an involuntary retirement status under section 2055(a) of this title, if qualified thereunder. Retirement rights under this paragraph shall be based on the provisions of this subchapter in effect as of the date on which the disability annuity is discontinued.
If, based on a current medical examination, the Director determines that a recovered annuitant has, before reaching age 62, again become totally disabled due to recurrence of the disability for which the annuitant was originally retired, the annuitant’s terminated disability annuity (same type and rate) shall be reinstated from the date of such medical examination. If a restored-to-earning-capacity annuitant has not medically recovered from the disability for which retired and establishes to the Director’s satisfaction that the annuitant’s income from wages and self-employment in any calendar year before reaching age 62 was less than 80 percent of the rate of pay for the grade and step the annuitant held at the time of retirement, the annuitant’s terminated disability annuity (same type and rate) shall be reinstated from the first of the next following year. If the annuitant has been allowed an involuntary or voluntary retirement annuity in the meantime, the annuitant’s reinstated disability annuity shall be substituted for it unless the annuitant elects to retain the former benefit.
An individual is not entitled to receive an annuity under this subchapter and a concurrent benefit under subchapter I of chapter 81 of title 5 on account of the death of the same person.