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.